The Russian military warned the United States today that it has enough weaponry to overwhelm any anti-ballistic missile system, and it threatened to deploy more atomic warheads if the United States builds a national missile defense system.

Nikolai Mikhailov, the first deputy defense minister, told reporters that "our arsenal has such technical capabilities" to "overcome" any antimissile defenses. "This technology can realistically be used and will be used if the United States pushes us toward it," he said.

His comments came on the heels of the latest meeting between Russian and American officials last week to discuss possible amendments to the 1972 Anti-Ballistic Missile Treaty. The Russian military adamantly opposes any changes to the treaty, which prohibits both countries from building systems capable of stopping missile attacks.

The Clinton administration has said it will decide next summer whether to go ahead with a limited missile defense system, which would require changing or abandoning the treaty. Russian officials have responded with increasingly vocal warnings that such a move could unravel two decades of arms control efforts.

Russia's key method of trying to overcome any missile defenses would be to deploy more nuclear warheads atop its missiles, in the calculation that it could outnumber and penetrate any defensive shield. Mikhailov did not offer specifics, but he said it was easier for Russia to deploy more warheads than for the United States to build an effective defense against them. "Russia's expenses would be several times . . . lower than the cost of implementing plans for setting up a national missile defense system," he said.

He also said Russia could target any ABM facility with a nuclear warhead.

One way Russia could gain more warheads would be to slow the dismantlement of existing multiple-warhead missiles. Another way would be to turn the single-warhead Topol-M missile, now being deployed in limited numbers, into a three-warhead delivery system. The Topol-M also has what Russian officials have described as countermeasures against an antimissile system, such as a lower trajectory and shorter engine burn, which would help missiles dodge a space-based tracking system.

However, there are major obstacles to any Russian attempts to expand its nuclear arsenal. Prolonging the life of existing missiles could be costly. Many missiles have already passed the period in which they were to have been taken down. In addition, Russia has no resources to design and build new weapons. Even the most modern missile, the Topol-M, is being deployed at a rate of only 10 missiles a year.

Ilya Klebanov, the deputy prime minister in charge of the military-industrial complex, said Friday that while "we have every technical means" to proceed if the United States pulls out of the ABM treaty, "there's no funding."

Mikhailov, speaking to Russia's Council on Foreign and Defense Policy, an elite group of policymakers, also said that Russia lacks resources for an up-to-date conventional military force. Referring to the high-tech weaponry that NATO deployed in last spring's bombing campaign against Yugoslavia, he said such advanced weapons make up only 30 percent of Russia's armed forces, compared with 80 percent in the West.

"This will cost us dearly," he said. "We will not catch up to Western countries in 10 or 15 years."