Russian President Vladimir Putin arrived in Camp David, Maryland, on Friday and began talks with US President George W. Bush.
Putin came to the US presidential retreat after attending the 58th United Nations General Assembly held in New York.
The two leaders will continue their talks on Saturday morning before concluding their two-day summit with a joint press conference.
The weekend summit will cover a wide range of issues of bilateral concerns. Top on their agenda will be Iraq, Iran, the Middle East and the nuclear issue of the Democratic People's Republic of Korea.
Bush and Putin met in June in Russia's St. Petersburg before heading for Evian, France to attend the annual summit of the Groupof Eight.