David Cameron, the British prime minister, has arrived in Moscow for a landmark visit - the first by a British leader to the Russian capital since a former Russian spy died in London from radioactive material poisoning in 2006.
Cameron will meet Russian President Dmitry Medvedev and Vladimir Putin, the prime minister, on Monday, with aims to strengthen business and political ties despite a long-running dispute over the murder of Alexander Litvinenko , a former KGB colonel and an outspoken Kremlin critic who had moved to Britain.
"Although our differences in recent years are well known, we face many similar challenges and both the president [Medvedev] and I believe that we can make more progress by working together on matters of real importance for the prosperity and security of people in both countries," Cameron said in a statement before
Cameron's office said the one-day visit, on which he was accompanied by a high-powered 24-strong business delegation, was expected to seal $345m worth of business deals, creating almost 500 new jobs in Britain and safeguarding thousands more.
The two countries are expected to agree to strengthen co-operation in civil nuclear energy.
That will put British firms in a good position to bid for work on projects with Russian atomic energy agency, potentially worth more than $1.6bn, Cameron's office said.
The visit is consistent with Cameron's strategy of trying to bolster Britain's weak economic recovery by boosting exports to fast-growing emerging markets such as Russia, India and China.
Bilateral relations have plunged to a post-Cold War low since Litvinenko died from being poisoned with radioactive polonium-210.
Both the UK and Russia expelled diplomats while Moscow refused a long-standing request from London to extradite Andrei Lugovoi, an ex-KGB bodyguard who Britain wanted to prosecute for Litvinenko's murder.
Cameron is expected to raise the Litvinenko issue and some human rights cases, but no progress is expected during the visit on resolving them.
Medvedev said Monday that the Kremlin would not bow to London's demand to hand Lugovoi over.
"This is not possible," he said. "We all have to learn to respect our legal norms."
"A Russian citizen may not be extradited or handed over to a foreign state for legal proceedings or an investigation."
It is also unlikely that the two parties will achieve progress on the issue of lifting the sanctions Britain imposed, including halting co-operation with Russia's security services and suspending talks on speeding up visa issuance.
Four former British foreign ministers urged Cameron on Sunday to raise human rights cases with Medvedev, including a perceived failure to protect business against corruption.
"These concerns need to be addressed before business can truly flourish," the former ministers wrote in a letter to The Sunday Times newspaper.
Some 600 British companies operate in Russia and British exports to Russia are up by 63 per cent in the first half of this year, according to the British government.
But British firms sometimes encounter problems in Russia.
Last month, special forces raided Moscow offices of British Petroleum (BP), a day after US giant ExxonMobil signed a deal giving it access to Russian Arctic oilfields that BP had tried to develop, only for its plans to be scuppered by a legal case.