Kurt Volker, the US ambassador to Nato, said: "If true, this would of course be a very positive step."

Barack Obama, the US president, spoke to Dmitry Medvedev, the Russian president, by telephone on Monday, in their first contact since the US inauguration.

The two men agreed to stop the "drift" in their countries' relations, the White House said on Tuesday.

Softer stance

The administration of George Bush, the former US president, angered the Kremlin with its push to deploy interceptor missiles in Poland and a radar in the Czech Republic.

It said the system was needed to protect from potential missile strikes by what it called "rogue states" - specifically Iran and North Korea.

Bush, left, angered the Kremlin with its push to deploy missiles in Poland [AFP]
Russia has argued that the proposed system would threaten its own national security and was further evidence - along with the eastward expansion of the Nato alliance - of Western military influence encroaching near its borders.

Medvedev later qualified his remarks on deploying Iskander missiles to Kaliningrad, saying that would only go ahead if Washington made the first move by starting work on its missile shield installations.

The row over the shield has helped drive diplomatic ties between Moscow and Washington to their lowest level since the end of the Cold War.

But Russian officials have said they are encouraged by early signals from the Obama administration and hopeful of a fresh start in their relations.

It is possible the Kremlin will be seeking a reciprocal concession from the White House when Medvedev meets Obama on the sidelines of a Group of 20 summit in London on April 2.