Moscow - Russia hopes talks between President Dmitry Medvedev and US President Barack Obama next month will set a concrete agenda to replace a key nuclear control treaty set to expire in December, the foreign ministry said Friday.

"We hope that the London talks will lead to concrete instructions on what parameters and what tempo negotiations will proceed," Deputy Foreign Minister Sergei Ryabkov told journalists.

Previous negotiations for a successor to the START Treaty on nuclear arms reduction hit choppy waters as ties between the two Cold War foes deteriorated over a host of security difference under Obama's predecessor George W Bush.

But Medvedev said Friday he was counting on a "reset" in relations in talks with Obama in London on the sidelines of the G20 summit on April 1.

Ryabkov repeated "optimism" for improved ties with Washington and the Obama administration, including in the START treaty negotiations.

"We think that on key issues, the differences which existed between the positions of Russia and previous administration will become several times less with the new administration," Ryabkov said. (dpa)