MOSCOW -- The American and Russian defense chiefs reported modest progress Monday toward a nuclear arms agreement but gave no indication they had settled the major stumbling blocks.

"We're making progress, and the meetings will continue later this week in Washington," Defense Secretary Donald H. Rumsfeld said, referring to meetings scheduled between Secretary of State Colin Powell and Russian Foreign Minister Igor Ivanov.

After about two hours of talks with Rumsfeld, Russian Defense Minister Sergei Ivanov told reporters that his government had submitted to the Americans a "set of new ideas" to push the talks toward agreement. He did not elaborate but said Rumsfeld had responded to those ideas.

"My personal belief is that today we have reached some progress," the defense minister said.

Summit in the works

The two also reviewed progress in the war on terrorism and discussed preparations for a U.S.-Russian summit in May. The Russian foreign minister is expected to meet with President Bush while in Washington in early May.

Rumsfeld flew here from Astana, Kazakstan, where President Nursultan Nazarbayev told him Sunday his government is ready to join the international humanitarian aid effort in Afghanistan and establish a liaison office at U.S. Central Command's headquarters in Tampa, Fla.

After the Moscow meeting Rumsfeld headed to Washington, completing a five-nation tour to bolster support for the war on terrorism from leaders in Kyrgyzstan, Afghanistan, Turkmenistan and Kazakstan.

U.S. and Russian negotiators have been working on a nuclear arms reduction deal they hoped would be ready for Bush and President Vladimir Putin to sign at their May summit meeting. The talks have snagged, however, over Moscow's objection to the Pentagon's decision to store nuclear weapons that it takes out of active service rather than destroy them.

A senior U.S. defense official traveling with Rumsfeld said en route to Moscow that Washington would not give up its plan to store some warheads as a hedge against unexpected shifts in the international security picture.

"It's a fact of life" that the Russians must accept, the official said, speaking on condition of anonymity.

Cooperation questioned

As for the war on terrorism, Russia's intelligence services are said to be troubled by what they see as a lack of cooperation from their U.S. counterparts.

On Sunday, Rumsfeld appealed to the rulers of two former Soviet republics for their continued assistance in stabilizing Afghanistan and denying new sanctuaries for al-Qaida fighters.

He stopped in Turkmenistan to see President Saparmurat Niyazov and then in Kazakstan's capital for talks with Nazarbayev.

Kazakstan's defense chief, Mukhtar Altynbayev, said his government planned to increase its involvement in Afghanistan. He mentioned transporting and donating humanitarian aid, and working out an agreement so U.S. and allied aircraft could use at least one Kazak airfield in case of emergency.

Kazakstan already allows allied coalition aircraft to use its airspace.