President Bush told Russian President Vladimir Putin on Friday that the United States supports a proposal from Moscow that could deny Iran the ability to produce nuclear weapons.

"It may provide a way out," National Security Adviser Stephen Hadley said of the Russian plan, discussed during an hourlong meeting between the U.S. and Russian presidents that ranged across a variety of difficult topics.

Putin is often criticized in the West for rolling back democratic progress by imposing state control of national broadcasters, scrapping elections for regional governors, and dismantling the Yukos oil company giant after its former CEO opposed the Russian leader.

U.S. officials' concerns have grown with the introduction of legislation last week in Russia's State Duma by members of Putin's party that would keep foreign non-governmental organizations from operating offices in Russia and deny foreign funds to Russian organizations that engage in certain political activities.

Two former vice presidential candidates, Republican Jack Kemp and Democrat John Edwards, had urged Bush to bring up the issue with Putin. "If this proposal comes into force, the government will clearly have in its hands the authority to close down public organizations simply because it finds their views and activities inconvenient," Kemp and Edwards wrote Bush. They are co-chairmen of a Council on Foreign Relations task force on Russia.

Hadley said Bush raised the matter with Putin but would not describe what he said. "Sometimes there are issues that can be more productively discussed out of public view," he said.

The Bush-Putin session on the sidelines of the annual conference of the Asia-Pacific Economic Cooperation (APEC) forum emphasized their shared fight against terrorism, Moscow's aspiration to join the World Trade Organization (WTO) by the end of the year, and the campaigns to stop North Korea and Iran from developing nuclear weapons.

Russia, a key Iranian ally, has refused to support Bush's eagerness to go to the U.N. Security Council with suspicions Iran is trying to build a nuclear arsenal. Also, over U.S. objections, Russia is building a nuclear reactor for a power plant in Iran and says it believes Iran's assurances the plant is for civilian energy use alone.

But Bush praised Putin for several steps Russia has taken that "would reduce the proliferation risks" in Iran, Hadley said.

Russia has helped bring Tehran back into European-led negotiations over its enrichment of uranium and reached agreement with Iran that any spent fuel rods from the plant would be sent back to Russia. And Bush expressed support for a Russian plan that would allow Iran to convert uranium but move the enrichment process to a facility to be built for Iran in Russia, Hadley said.

In theory, that would deny Iran the capacity to produce weapons-grade uranium needed for nuclear weapons.

Though Iran has "not surprisingly" so far rejected the idea, Hadley said: "We think that doesn't end it. This will be an issue we will return to."

The pace of democratic progress under Putin's leadership has increasingly become a sour note in Bush's meetings with his Russian counterpart, clouding a relationship that quickly moved to a first-name basis and became stronger after the 2001 terrorist attacks.

But appearing in a hotel suite for their fifth meeting of the year, the pair projected only warm smiles and friendly chitchat. "Hey Vladimir. How are you? Looking good," Bush said, tapping the Russian on the back.

"The dynamic in the room was very positive, very loose," White House counselor Dan Bartlett said.

As Bush and Putin projected solidarity, a crack appeared in the united front presented a day earlier by the president and South Korean President Roh Moo-hyun. Catching the White House by surprise, the South Korean Defense Ministry announced Friday it will include plans to bring home about a third of its 3,200 troops in Iraq when it seeks parliamentary approval for extending the deployment.

Foreign Minister Ban Ki-moon said the South Korean government will make a decision on troop deployment levels based on the situation in Iraq and domestic demands.

National Security Council spokesman Frederick Jones said no notice had been given to the Bush administration on an issue — South Korea's contributions to the military coalition in Iraq — that had been a positive topic of discussion in Bush and Roh's talks Thursday.

At the APEC meetings that got underway Friday in this port city, the 21 leaders were focusing on two items important to Bush. The leaders were hoping to make a strong statement capitalizing on their combined clout — the countries represent nearly half of global trade — to reinvigorate stalled talks on a worldwide free-trade pact. New WTO talks are set for next month in Hong Kong.

They also were pledging united efforts to reduce the risk of a global flu pandemic.

Outside at barricades near the meeting, riot police sprayed high-powered water hoses Friday to hold back about 4,000 demonstrators chanting "No Bush! No APEC." Some demonstrators threw rocks and bamboo sticks at the police. The rally lasted several hours and 11 officers were injured, police said.

Bush was to attend the final APEC sessions Saturday, meet separately with Indonesian President Susilo Bambang Yudhoyono and then fly to Osan Air Base south of Seoul to speak to U.S. troops. Later in the weekend, he was to meet Chinese President Hu Jintao in Beijing and stop in Mongolia to finish his four-country Asian swing.