WASHINGTON -President Barack Obama declared Thursday that he and Russian President Dmitry Medvedev have "succeeded in resetting" the relationship between the former Cold War adversaries that had dipped to a dangerous low in recent years.

Medvedev expressed hope that Moscow and Washington would ratify the new strategic arms reduction treaty in the near future.

"I hope it will be done as soon as possible," Medvedev said at a news conference with his US counterpart, Barack Obama.

Medvedev and Obama agreed that the ratification processes should be simultaneous.

Russia and the United States signed the new treaty on the reduction of strategic offensive weapons in Prague on April 8. The document will replace the START 1 treaty, which expired in December 2009.

Obama directly acknowledged differences in some areas, such as Moscow's tensions with neighboring Georgia, but said "we addressed those differences candidly." And he announced that the US and Russia had agreed to expand cooperation on intelligence and the counterterror fight and worked on strengthening economic ties between the nations.

Obama gave Russia perhaps the biggest gift it could have wanted from the meetings: an unqualified, hearty plug for Moscow's ascension to the World Trade Organization. Russia has long wanted membership but U.S. support in the past has come with conditions.

"Russia belongs in the WTO," Obama said as the two leaders stood side-by-side in the East Room after several hours of meetings _ including an impromptu trip to a nearby hamburger joint for lunch.

The leaders faced questions about the US-led Afghanistan war, and Obama promised that the US will "not miss a beat" because of the change in military command that he ordered on Wednesday. Obama accepted Gen. Stanley McChrystal's resignation and replaced him with his direct boss, Gen. David Petraeus.

Petraeus "understands the strategy because he helped shape it," Obama said.

Medvedev seemed reluctant to wade into the topic, recalling the ultimately disastrous Soviet invasion of Afghanistan in 1979.

"I try not to give pieces of advice that cannot be fulfilled," Medvedev said. "This is a very hard topic, a very difficult one."

Yet he said that Russia supports the U.S. effort if it can result in Afghanistan emerging from extreme poverty and dysfunction to have "an effective state and a modern economy."

"This is the path to guarantee that the gravest scenarios of the last time will not repeat," he said.

Obama said the two had also agreed to coordinate on humanitarian aid for Kyrgyzstan, wracked by deadly unrest in the wake of the president's ouster there. Kyrgyzstan's president was driven from power in April amid corruption allegations, sparking violence that has left about 2,000 people dead and 400,000 ethnic Uzbeks homeless.  

The agenda for Obama and Medvedev was modest, and mostly focused beyond security issues to expanding trade and economic cooperation. Russia has the world's eighth-largest economy but ranks 25th among U.S. trading partners.

Obama said the two countries had reached an agreement to lift restrictions that have hindered US poultry exports to Russia, removing a major irritant in trade relations. Russia, a major poultry importer, banned all chlorine-treated poultry imports starting January 1, outlawing the 600,000 tons of poultry allowed from the U.S. under revised quotas. US farmers accounted for 20 percent of the 3.5 million tons of poultry Russia consumed last year.

Obama said the agreement "sends an important signal about Russia's seriousness about achieving membership in the WTO."

"The true significance of Medvedev's visit is that it brings us closer to a relationship that doesn't require Cold War-style summits to sustain itself," says Sam Charap, a Russia analyst at the Center for American Progress. "The lack of headlines is actually a sign of progress."

Medvedev arrived at the White House on a sweltering summer morning for a series of meetings with Obama and US officials. It was their seventh meeting since Obama took office 17 month ago.

Leaving the formality of the White House, they sneaked away for an impromptu ride across the Potomac River to a popular hamburger joint _ Ray's Hell Burger in Arlington, Va. Customers cheered when the two walked in.

Later, at the news conference, Medvedev called the burgers "probably ... not quite healthy but it's very tasty."

After their joint news conference, Obama and Medvedev were going together to the US Chamber of Commerce.

Ahead of the talks, US officials pointed to signs that Obama's much-heralded efforts to start fresh with Moscow have delivered results, from Russian support for new UN sanctions against Iran over its disputed nuclear program to the signing of a major treaty to reduce the two countries' stockpiles of nuclear weapons. They say the US is standing its ground with Russia but shifting the tone away from conflict.

Medvedev began his US visit in California, where he toured Silicon Valley high-tech firms as part of his push to establish a high-tech center in Russia.