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.