(CNN) -- The United States officially recognized Kosovo -- the Balkan state which split from Serbia on Sunday -- as an independent nation on Monday, Secretary of State Condoleezza Rice said in a written statement.
"We congratulate the people of Kosovo on this historic occasion," Rice said.
"President Bush has responded affirmatively to a request from Kosovo to establish diplomatic relations between our two countries."
UK Prime Minister Gordon Brown said: "Britain will now formally recognize Kosovo as an independent sovereign state."
France said it would recognize Kosovo, and is in the process of confirming that in writing. Germany indicated its support would come.
But other EU nations including Greece, Spain and Romania have signaled that they would not follow suit amid concerns about the precedent that such a move would set.
"The unusual combination of factors found in the Kosovo situation -- including
the context of Yugoslavia's breakup, the history of ethnic cleansing and crimes
against civilians in Kosovo, and the extended period of U.N. administration --
are not found elsewhere and therefore make Kosovo a special case. Kosovo cannot
be seen as a precedent for any other situation in the world today."
The Security Council is meeting Monday to discuss Kosovo and Serbian president Boris Tadic is expected to emphasize his country's opposition to Kosovo's breakaway. Watch how U.N. is divided over Kosovo's future »
About 100,000 Serbs still live in Kosovo, making up about 5 percent of the population. Sejdiu pledged to create a nation "where all citizens of all ethnicities feel appreciated."