This Monday, President Trump declared that the Houthi insurgents in Yemen, who were backed by Iran, had been “decimated by the relentless strikes” that he had authorized starting on March 15.

Pentagon and military officials, however, are not quietly informing Congress and allies that.

According to congressional aides and friends, Pentagon officials have admitted in confidential meetings in recent days that the Houthis’ extensive, mostly subterranean stockpile of missiles, drones, and launchers has only been partially destroyed.

According to the individuals informed on sensitive damage estimates, the bombing is far larger than what the Defense Department has officially said and consistently heavier than attacks carried out by the Biden administration.

However, according to three congressional and allied officials who spoke on condition of anonymity to discuss operational matters, Houthi fighters have strengthened many of their bunkers and other targeted sites, making it more difficult for the Americans to stop the militia’s missile attacks against commercial ships in the Red Sea.

In addition to the enormous operational and manpower expenditures to deploy two aircraft carriers, more B-2 bombers and fighter fighters, and Patriot and THAAD air defenses to the Middle East, the Pentagon has spent $200 million on bombs in only three weeks, the officials said.

By next week, it may cost well over $1 billion, and the Pentagon may soon have to ask Congress for additional funding, according to a U.S. official.

Some Pentagon contingency planners are becoming concerned about total Navy stockpiles and the consequences for any scenario in which the United States would have to repel a Chinese invasion attempt of Taiwan since so many precise bombs, particularly sophisticated long-range ones, are being deployed.

Operation Rough Rider, named by Defense Secretary Pete Hegseth after the forces Theodore Roosevelt commanded in Cuba during the Spanish-American War, is expected to last for six months, according to authorities.

Late Thursday, a senior Pentagon officer retracted the judgments that the congressional and allied officials had stated.

Speaking on the condition of anonymity to discuss operational matters, the senior official also claimed that the airstrikes had gone beyond their initial objective in the campaign, interfering with senior Houthi leaders’ communication, restricting the group’s ability to respond to a few ineffectual counterattacks, and laying the groundwork for later phases, which he would not discuss. “We’re on schedule,” the official declared.

According to U.S. authorities, the Houthis’ command and control system was harmed by the attacks. In a statement, national intelligence director Tulsi Gabbard said that the operation was reopening Red Sea shipping and that the attacks had been “effective” in killing key Houthi commanders, whom she did not name.

Ms. Gabbard stated, “Intelligence community assessments confirm that these strikes destroyed several facilities the Houthis may use to produce advanced conventional weapons and killed top Houthi leaders.”

The attacks are at the heart of a scandal involving Mr. Hegseth and other high-ranking Trump administration officials who, in a group conversation on a for-profit messaging app, shared private information regarding the first bombing missions in Yemen on March 15. The group was formed by national security adviser Michael Waltz, who unintentionally included a journalist.

The goal of the air and naval raids, according to Trump administration officials, is to put pressure on the Houthis to stop their attacks, which have been interfering with international maritime channels in the Red Sea for over a year.

Although on a lower scale and mostly targeting military and infrastructure targets, the Biden administration did launch operations against the Houthis. Officials from the Trump administration claim that key Houthi officials are also intended to be killed by the present strikes.

Last week, Secretary of State Marco Rubio told reporters, “Everyone should realize we are doing the world a great favor going after these guys, because this can’t continue.”

Following the Biden administration’s year-long attempt to discourage the Houthi strikes, which have also targeted Israel, the Trump administration has not explained why it believes its campaign against the organization would be successful.

This week, Senators Rand Paul, a Republican from Kentucky, and Jeff Merkley, a Democrat from Oregon, wrote to Mr. Trump, saying, “The administration must also explain to Congress and the American people its expected path forward given the failure of previous such efforts.”

Since March 17, when it claimed that over 30 Houthi sites had been struck on the first day, the Pentagon has not released any information on the attacks.

The attacks “destroyed command-and-controlled facilities, air defense systems, weapons manufacturing facilities, and advanced weapons storage locations,” according to a statement released on March 24 by a spokeswoman for the military’s Central Command.

“We have already started to see the effects of the heavy strikes against the Houthis,” a senior Defense Department official stated Thursday in response to inquiries from The New York Times. For example, the Houthis have stopped attacking Israel with ballistic missiles throughout the past week.

“As the U.S. airstrikes degrade their capability and capacity, the Houthis are becoming more and more reactive,” the senior official stated.

The senior source denied that Pentagon briefers had informed congressional and allied officials that the strikes may extend six months, stating that the duration “has NEVER been discussed.” The official spoke on condition of anonymity to discuss operational concerns.

Images of planes executing sorties against the Houthis are shared on social media by Central Command, but it has consistently declined to provide the number of targets hit thus far or to name the numerous Houthi leaders, including a senior missile specialist, whom it claims to have killed.

The types of longer-range munitions that Navy F/A-18 Super Hornets have fired on Yemen are demonstrated in videos that Central Command has shared on social media. These include of air-launched cruise missiles and the GPS-guided glide bomb known as the AGM-154 Joint Standoff Weapons.

The glide bombs may be fired over 70 nautical miles away from their targets and each one carries 200 pounds of explosives. Navy jets can carry cruise missiles more than twice as far.

They have been utilized in conjunction with Tomahawk cruise missiles fired by accompanying warships and are among the longest-range aerial weapons available to Navy fighters for use in such operations.

The threat presented by the Houthis’ air defense systems, which have destroyed many American military drones in the region, is the reason for the deployment of such long-range missiles. They are essential for any future battle with China, according to U.S. officers involved in Asia-Pacific strategy.

On March 15, the United States launched the latest operation in Houthi-controlled areas of northern Yemen. Every day since, U.S. and Yemeni forces launched attacks against Houthi targets using Navy attack planes from the Truman and Air Force fighter fighters operating from bases in the Middle East.

According to top U.S. officials, the first attacks were the first of a new effort against the terrorists and a message to Iran as Mr. Trump attempts to negotiate a nuclear agreement with its government.

A few Arab countries who are concerned about the Houthis’ aggressiveness in the area have received Patriot and THAAD air defense systems from the Pentagon. According to a U.S. official, the United Arab Emirates is providing the U.S. military with advising and logistical support throughout its war in Yemen.

For more than six years, Saudi Arabia spearheaded a bombing campaign against the Houthis alongside the Emirates and other countries, but it halted after achieving no results. Many Yemeni civilians were murdered by the Saudi-led coalition using ammunition provided by the United States.

Commanders claim that because Mr. Trump has given regional and local commanders more latitude to strike targets than President Joseph R. Biden Jr., they can hit Houthi locations more swiftly and effectively.

According to Houthi authorities, more than 60 civilians have been killed as a consequence of the attacks that targeted residential neighborhoods and structures in the center of Sana, Yemen’s capital.

A mother and four children were reportedly killed in one of the raids on March 15, according to a report issued Thursday by Airwars, a British group that evaluates allegations of civilian casualties in conflicts.

The fact that many of the assaults happened in densely populated regions, according to the study, “indicates a higher tolerance to the risk of civilian harm and suggests that the Trump administration is choosing targets that pose a more direct risk to civilians.”

The Pentagon looks at all reports of civilian casualties, according to a U.S. official who stated on Thursday that the military takes every precaution to lower the dangers.

“The Houthis have waged an unrelenting campaign of piracy, violence, and terrorism against American, and other, ships, aircraft, and drones,” Mr. Trump stated on social media on the first day of the new attack.

U.S. strikes will continue until the Houthis “are no longer a threat to Freedom of Navigation,” according to Mr. Trump’s statement this week. If they didn’t stop, he said, “the real pain is yet to come.”

Mr. Trump also singled out Iran’s leaders on March 15.

His post was titled “To Iran: Support for the Houthi terrorists must end IMMEDIATELY!” “Never endanger the American people, their president, who has been given one of the most powerful orders in the history of the presidency, or international shipping lanes.” America will hold you totally responsible, so if you do, BEWARE.

Produced in underground factories and smuggled in from Iran, Houthi weapons systems have proven difficult for U.S. intelligence services to detect and track down. The Biden administration increased its use of observation planes to learn more about Houthi targets in late 2024. According to the U.S. sources, Trump administration inherited that intelligence and Israel also provided target information.

Julian E. Barnes from Washington and Saeed Al-Batati from Al Mukulla, Yemen, provided reporting.