Moscow - US President Barack Obama has arrived in Moscow ahead of talks with his Russian counterpart Dmitry Medvedev which will aim to reduce the two countries' nuclear stockpiles. The issue of the conflict in Afghanistan, plus relations with Iran and North Korea are also to be on the agenda.
The president's plane, Air Force One, touched down amid rain at the Russian government's airbase at Vnukovo on Monday morning.
Both countries have said that they want to reduce their nuclear warhead stockpiles to 6,000 each.
Both presidents have also expressed a desire to improve relations between the two states, which have been strained of late, over Russia's war with Georgia in the summer of 2008, and a prospective US plan to station a missile defence system in eastern Europe.
On Saturday, Gary Samore, advisor to President Obama on questions of weapons of mass destruction, said in Moscow that progress on arms reduction was expected.
The US and Russia at the meeting are expected to work towards a replacement deal for the 1991 Strategic Arms Reduction Treaty, or START, which expires December 5.
The two men are expected to sign an agreement - although likely not a final deal to replace START - on nuclear weapons over the course of the two-day talks. However a number of potential stumbling blocks remain, Samore said.
For example, he said, questions remain about the counting of warheads and missiles, as well as the verifiability of disarmament steps.
Medvedev has both linked the disarmament deal to a cancellation of the US' missile defence plan, and appeared to be conciliatory on the issue.
The Moscow newspaper Kommersant reported on Monday that the two sides had not yet ironed out their differences on whether or not a cancellation of the missile-defence system should be a precondition to the nuclear reduction deal.
However in addition to the armaments talks, Russia and the US are expected to sign a deal which will allow US Army transport flights to pass over Russia on the way to Afghanistan.
Until now, only rail transport carrying non-lethal goods has been allowed.
On Monday Russian newspapers however expressed scepticism over whether the meeting signified a new start - or "reset" - in relations between the two states.
Sticking points include disagreements over Russia's membership of the WTO, the status of the Georgian breakway republics of South Ossetia and Abkhazia, the prosecution of Russian oil billionaire Mikhail Khordokovsky and other issues.
Russia has also been the only G8 country to acknowledge Iranian President Mahmoud Ahmadinejad as the clear victor in the disputed June 12 election.
Obama is to meet with Prime Minister and ex-president Vladimir Putin on Tuesday, as well as representatives of Russian human-rights organizations. Obama has been accompanied on his trip by his wife Michelle and both daughters.
Obama is then to fly to Italy where he will attend the G8 meeting in L'Aquila. The agenda there is to include the global recession, climate change and the situations in Iran and the Middle East.
The G8 summit comes ahead of the larger Group of 20 nations planning to meet in September in the US city of Pittsburgh, Pennsylvania, to discuss the economic crisis. Obama has been at odds with his European counterparts, who want to see more regulation of US financial markets.
In Ghana, Obama plans to outline his Africa policy in a speech during his first visit as president to the continent. Obama has in years past visited Kenya, the homeland of his late father.
