MOSCOW. May 12 (Interfax) - Finishing his stint as U.S. ambassador to Russia, William Burns left Moscow for Washington on Monday to take up his new position as under secretary of state for political affairs, the third highest rank in the State Department, a spokesman for the U.S. Embassy in Moscow told Interfax.

Late last week, the U.S. Senate unanimously confirmed Burns as under secretary.

It has not yet been announced who will replace him in Moscow. Deputy Chief of Mission Daniel Russell is succeeding him provisionally as charge d'affaires.

In an interview with Interfax before his departure, Burns said he expected U.S.-Russian relations to be high on his agenda in his new capacity.

He expressed hope to have more than one chance of coming back to Russia on both official and private visits.

Burns said he and his family had spent five years in Russia altogether, two of them in the 90s and three when he was ambassador.

He said he would think of Russia with admiration and respect.

The diplomat also said that, at a meeting in Sochi, Russia, last month, U.S. president George W. Bush and his then Russian counterpart, Vladimir Putin, planned a meeting of a working group on terrorism for June.

Burns expressed satisfaction with cooperation between American and Russian law enforcement authorities in combating terrorism and with the exchange of intelligence between the United States and Russia in fighting terror.

He mentioned efforts to deprive terrorist groups of funding as one aspect of this cooperation.

Burns said that, during his ambassadorial stint, he had sought to defend U.S. interests, understand Russian points of view and show respect for them.

The ex-ambassador said he had been looking for points of contact and trying to be honest about disagreements between the United States and Russia. He said he had not tried to seem complaisant when he disagreed.