The Navy admiral had a blunt message for the military contractors building precision-guided missiles for his warships, submarines and planes at a moment when the United States is dispatching arms to Ukraine and preparing for the possibility of conflict with China.

“Look at me. I am not forgiving the fact you’re not delivering the ordnance we need. OK?” Adm. Daryl Caudle, who is in charge of delivering weapons to most of the Navy’s East Coast-based fleet, warned contractors during an industry gathering in January. “We’re talking about war-fighting, national security, and going against a competitor here and a potential adversary that is like nothing we’ve ever seen. And we can’t dillydally around with these deliveries.”

His open frustration reflects a problem that has become worryingly apparent as the Pentagon dispatches its own stocks of weapons to help Ukraine hold off Russia and Washington warily watches for signs that China might provoke a new conflict by invading Taiwan: The United States lacks the capacity to produce the arms that the nation and its allies need at a time of heightened superpower tensions.

Industry consolidation, depleted manufacturing lines and supply chain issues have combined to constrain the production of basic ammunition like artillery shells while also prompting concern about building adequate reserves of more sophisticated weapons including missiles, air defense systems and counter-artillery radar.

The Pentagon, the White House, Congress and military contractors are all taking steps to address the issues.

Procurement budgets are growing. The military is offering suppliers multiyear contracts to encourage companies to invest more in their manufacturing capacity and is dispatching teams to help solve supply bottlenecks. More generally, the Pentagon is abandoning some of the cost-cutting changes embraced after the end of the Cold War, including corporate-style just-in-time delivery systems and a drive to shrink the industry.

“We are buying to the limits of the industrial base even as we are expanding those limits,” Deputy Defense Secretary Kathleen Hicks said this month at a briefing on the Biden administration’s 2024 budget plan.

But those changes are likely to take time to have an effect, leaving the military watching its stocks of some key weapons dwindle.

In the first 10 months after Russia invaded Ukraine, prompting Washington to approve $33 billion in military aid so far, the United States sent Ukraine so many Stinger missiles from its own stocks that it would take 13 years’ worth of production at recent capacity levels to replace them. It has sent so many Javelin missiles that it would take five years at last year’s rates to replace them, according to Raytheon, the company that helps make the missile systems.

If a large-scale war broke out with China, within about one week the United States would run out of so-called long-range anti-ship missiles, a vital weapon in any engagement with China, according to a series of war-game exercises conducted by the Center for Strategic and International Studies, a Washington-based think tank.

The shortcomings in the nation’s defense industrial base are vividly illustrated by the shortage of solid rocket motors needed to power a broad range of precision missile systems, like the ship-launched SM-6 missiles made by Raytheon.

It was the shortage of SM-6 missiles in particular that had Admiral Caudle fuming; they are used to defend ships against enemy aircraft, unmanned aerial vehicles and cruise missiles.

There are only two contractors today that build large numbers of rocket motors for missile systems used by the Air Force, the Navy, the Army and the Marines, down from six in 1995.

A recent fire disrupted the assembly line at one of the two remaining suppliers, Aerojet Rocketdyne, causing further delays in delivering the SM-6 and other precision missile systems, even as Pentagon orders for thousands of new missiles pile up.

“Rocket motors, a bane of my existence, continued to be a problem,” Gregory Hayes, Raytheon’s chief executive, told Wall Street analysts last month. He said the shortage would affect the company’s ability to deliver new missiles on time and was a problem unlikely to be solved “until probably the middle of ’24.”

Aerojet is building motors for older systems such as Javelin anti-armor missiles and Stinger antiaircraft missiles, of which over 10,000 have already been sent to Ukraine. It is also building new rockets needed to power so-called hypersonic missiles that can travel much faster, as well as the rockets for a new generation of nuclear weapons for the United States and even the rocket for a new NASA spaceship soon headed to the moon.

The result is billions of dollars in backlogged orders at the company — and frustration at the Pentagon about the pace of delivery.

“At the end of the day, I want the magazines filled,” Admiral Caudle told contractors and Navy personnel in January, referring to the storage areas on his ships for guided missiles. “OK? I want the ships’ tubes filled.”