President Donald Trump said Monday that the United States is rapidly replenishing its weapons stockpile after former President Joe Biden's administration transferred large quantities of ammunition and advanced military equipment to Ukraine.

Speaking to reporters aboard Air Force One, Trump dismissed concerns that the United States could face ammunition shortages if fighting with Iran resumes, although he acknowledged that inventories of some advanced weapons should be larger.

"We have a lot of ammunition, different types. You know, Biden gave a lot to Ukraine, so we're building that up. But we have a lot," Trump said.

"We have a lot of the mid-level stuff, too — I mean more than we could ever use no matter what. But we have a lot," he continued.

"I'd like to have more, to be honest, but so much was given to Ukraine by Biden."

Trump said the military had substantial weapons inventories when his first term ended in January 2021, but much of that equipment was later sent overseas after Russia launched its full-scale invasion of Ukraine in February 2022.

"When I left, the cupboards were full ... As soon as I left, they gave a lot of it to Ukraine — I mean, numbers that nobody's ever seen before," Trump said.

The president said his administration is expanding production capacity across the defense industry, with contractors developing multiple new manufacturing facilities.

"We're in very good shape. But for some of the more sophisticated stuff, we'd certainly like to have more," he said.

"Biden gave a lot of it away."

Trump said defense contractors are "building four to five plants" each and that the government is rebuilding its stockpile "very rapidly," pointing to increased production of Patriot air defense missiles.

The comments came amid scrutiny of U.S. weapons reserves following years of military assistance to Ukraine and nearly five months of conflict involving Iran.

The United States and Iran paused direct attacks for a third consecutive day Monday as Qatar, Pakistan, and Oman pursued back-channel diplomacy aimed at restoring an interim ceasefire.

Trump expressed optimism about the discussions but said the United States could return to military action if they fail. Iran said it was exchanging messages through mediators but denied that direct negotiations were underway.

Congress appropriated more than $174 billion for Ukraine and other countries affected by the war through early 2026, including military, economic, and humanitarian assistance, according to the Government Accountability Office.

Efforts to expand ammunition production have encountered setbacks.

A Pentagon inspector general's report found the Army produced about 36,000 155 mm artillery rounds per month as of March, well below its goal of 100,000, partly because a $469 million facility in Mesquite, Texas, had not produced projectile parts meeting contract specifications.

The administration has nevertheless continued pushing domestic production. Trump signed an executive order this month directing officials to strengthen defense supply chains, map vulnerabilities, and encourage contractors to qualify new domestic sources of critical materials and components.

The Associated Press contributed to this report.