Moscow - Sergei Kislyak, Russia's deputy foreign minister, was named the country's new ambassador to Washington, news agencies reported Tuesday.

Kislyak, 57, has headed difficult negotiations with the United States in recent months over Washington's plan to install parts of a missile defence shield in Eastern Europe.

The countries' conflicting security vision is one of a number of issues that makes for tense relations that show no signs of easing as Kislyak takes the post, despite a change of administrations in both capitals.

The two front-runners in the US presidential race have been strongly critical of former president Vladimir Putin, whose legacy his successor Dmitry Medvedev has pledged to follow.

Kislyak will replace veteran diplomat Yuri Ushakov, 61, who served as Russia's representative in Washington from 1999 throughout Putin's eight-year term presidency.

Putin in June tapped Ushakov to join his cabinet, feeding rumours he intends to retain influence over foreign policy in his new role as prime minister.

Kislyak, fluent in English and French, was Russia's envoy to NATO from 1998 to 2003 and is well versed in the security issues that are at the heart of US-Russia discord.

Moscow opposes the alliance's openness to the accession of post-Soviet states neighbouring Russia and views US plans as a threat to its nuclear deterrent. (dpa)