US President George W Bush and Russian President Vladimir Putin have signed a framework agreement but said they had made no breakthrough on differences.
Mr Putin said Russia remained opposed to US missile defence plans in Europe, but there were "positive developments". Mr Bush said there was still work to do to persuade Moscow that the system was not aimed at Russia.
Their farewell meeting, in the Russian Black Sea resort of Sochi, came a month before Mr Putin was due to stand down.
Russian President-elect Dmitry Medvedev also met Mr Bush, saying he hoped to continue advancing Russia-US relations.
The BBC's Gabriel Gatehouse in Sochi says that, at the news conference after the talks, the two leaders did not dwell on their differences and were on first name terms throughout.
They said they had agreed to intensify their dialogue.
"We agreed today that the United States and Russia want to create a system for responding to potential missile threats in which Russia and the United States and Europe will participate as equal partners," Mr Bush said.
"This is a powerful and important strategic vision."
Measures to ensure transparency and confidence-building would address Russian concerns, he added.
Mr Bush said he supported Russia's bid to join the World Trade Organization, and favoured removing the Jackson-Vanik amendment, tying trade relations to human rights issues.
Mr Putin said he welcomed US willingness to hear and discuss Russian questions about missile defence.
"I have a cautious optimism about agreement," he said.
"The devil is as usual in the detail. It is important that our experts agreed what confidence-building measures there will be and how they will be carried out in reality."
The summit began cordially, with the leaders joining a folk dance during dinner on Saturday evening at Mr Putin's holiday home.
And the following morning they met at a guest house in the presidential compound.
Mr Bush said as they exchanged pleasantries that the meeting would be "interesting".
"You're not afraid to tell me what's on your mind," he said, quoted by the Associated Press.
"When all is said and done, we'll shake hands. You've been a strong leader."
Mr Bush held separate talks with Mr Medvedev, who takes over as Russian president next month.
The president-elect said he wanted to carry on the work done by Mr Bush and Mr Putin to advance bilateral relations, which he described as a "key factor in international security".
Correspondents say the meeting will have given Mr Bush a chance to see how much power Mr Putin will continue to wield when he becomes prime minister.
Mr Bush described the president-elect as a "straightforward fellow".
"I was impressed and look forward to working with him," he said.
Their meeting follows a Nato summit in Romania where Mr Putin - a guest at the Bucharest gathering - warned against the Western military alliance's eastward expansion.
The summit also saw Nato countries agreeing to back the US missile plans during the Romanian summit.
On the issue of Nato expansion, Russia maintains that US plans to include Ukraine and Georgia will be viewed as a direct threat.
The two countries are seeking to become members of the alliance, but were not offered a fast-track "Membership Action Plan" at the summit.
The alliance has, however, left open the option of taking them in.