British Prime Minister David Cameron was on a state visit to Russia on Monday in a step toward repairing frosty relations between the two countries, DPA reported.
It was the first visit by a British Prime Minister to Moscow in six years, following the alleged assassination of a Russian defector in London by Kremlin agents in 2006.
Cameron was scheduled to meet with his Russian counterpart Vladimir Putin as well as President Dmitry Medvedev.
Talks were like to focus on energy, including a possible production increase by a British-Russian offshore drilling joint venture near Russia's Sakhalin island, and the problematic relationship between the British energy giant BP and Russian authorities, Interfax reported.
BP senior executives have said the Kremlin is using legal and official pressure to reduce and possible end BP's operations in Russia's energy-rich Arctic Sea territories - an allegation denied by Russian officials.
The British Prime Minister in a Monday morning speech to Moscow university students said he also intended in the Kremlin talks to bring up the case of the murder of Aleksandr Litvinenko, a renegade agent from Russia's national intelligence agency the FSB who fled to Britain in 2000.
British prosecutors have alleged three FSB assassins, one of whom now is a serving member of Russia's parliament, murdered Litvinenko by radiation poisoning in November 2006.
The murder scandal and the Kremlin's refusal to extradite suspects pushed Russo-British relations to a low ebb.