Russia (search) is prepared to reduce its strategic nuclear arsenal below 1,500 warheads, less than the level agreed to with the United States (search), but Moscow is concerned about nuclear threats on its border, two senior Russian officials said Monday.

Anatoly Antonov (search), director of the Foreign Ministry's department for security and disarmament, and Lt. Gen. Vladimir Verhovtsev, deputy director of the Defense Ministry's department of nuclear safety and security, stressed Moscow's commitment to nuclear disarmament — provided that Russia's security is assured.

The May 2002 U.S.-Russia Treaty (search) requiring each side to cut its deployed warheads by about two-thirds, to between 1,700 and 2,200 warheads by 2012, will be the focus of Moscow's efforts over the next decade, Verhovtsev said.

"We stand ready to take further constructive steps," he told a briefing on the sidelines of a U.N. conference to review the Nuclear Nonproliferation Treaty, adding that Russia is "ready to reduce to 1,500 warheads or less."

But Antonov said Russia needs international peace and security and "a situation where there are no new nuclear threats on our border."

The United States and Russia are the only countries that have taken serious steps to limit their nuclear arsenals, he said.

"What about other countries that continue to work on nuclear weapons?" Antonov asked, voicing concern about missiles and weapons being developed on Russia's borders but refusing to identify any country by name. China is the main nuclear power on Russia's border, but North Korea also claims to have nuclear weapons and is suspected of preparing for a nuclear test.

At the opening of the treaty review conference earlier this month, Secretary-General Kofi Annan (search) called on Washington and Moscow "to commit themselves — irreversibly — to further cuts in their arsenals, so that warheads number in the hundreds, not the thousands."

Under the Nuclear Nonproliferation Treaty, nations without nuclear weapons pledge not to pursue them, in exchange for a commitment by five nuclear states — the United States, Russia, Britain, France and China — to negotiate toward disarmament. The treaty guarantees countries that renounce nuclear weapons access to nuclear technology for peaceful purposes.

Some nuclear "have-nots" complain that the nuclear states are moving too slowly toward disarmament.

But Antonov said the environment for disarmament "depends on all of us," not just the United States and Russia. "We're telling our partners we can't close our eyes" to what's happening on Russia's borders and elsewhere in the world, he said.

Russia is against new states acquiring nuclear weapons and backs an early diplomatic solution to the North Korean threat, preferably through a resumption of six-party talks that have included Moscow, Antonov said. Russia also supports European-led talks to resolve questions about Iran's nuclear program and wants Tehran to provide clear assurances it is peaceful, he said.

The Russians presented a booklet outlining steps that Moscow has taken to cut its arsenal of nuclear warheads and intercontinental ballistic missiles, to eliminate intermediate- and short-range missiles, and to reduce tactical nuclear weapons.

It gave figures for all categories except tactical nuclear weapons, which Verhovtsev said had been reduced by 75 percent, though he couldn't provide numbers because of legislative restrictions.

The Russians were asked to explain why President Vladimir Putin (search) has announced the development of a nuclear missile system unlike any now in existence if they are serious about reducing their nuclear arsenal.

"Developing doesn't mean possessing," Verhovtsev replied.