NATO and Russian ambassadors will hold a last meeting on March 27, a week before an unprecedented summit between their leaders in Bucharest, a Russian mission diplomat said Thursday.
"We agreed with NATO upon an extraordinary and informal meeting on the 27th," the diplomat said, adding that talks between top US and Russian officials in Moscow this week would probably be discussed.
"We can predict that it will be on the results of US-Russian 2+2 discussions in Moscow, as well as Kosovo and any other item in connection with the Bucharest summit," he said.
He insisted the informal talks were "not an emergency meeting but a preparatory meeting".
Russia's ambassador to NATO, Dmitry Rogozin, told AFP on Monday that he had requested the informal meeting as "some urgent issues might come up that we will have to discuss." He declined to elaborate.
US Defense Secretary Robert Gates and Secretary of State Condoleezza Rice told President George W. Bush on Thursday that their trip to Russia had been "constructive," according to the White House.
Issues discussed included missile defense, counter-terrorism and counter-proliferation, a spokeswoman said.
Relations between Russia and NATO have been tense over the last year, notably due to differences over Kosovo's declaration of independence, a key Soviet-era arms pact that Moscow has frozen and the US missile shield.
Attempts by Georgia and Ukraine to join the military alliance are also a sore point.
Russian President Vladimir Putin is due to meet NATO's 26 heads of state and government on the last day of the military alliance's April 2-4 summit in the Romanian capital.