Updated 11:27 AM ET November 22, 1999

 By Randall Mikkelsen

 SOFIA, Bulgaria (Reuters) - President Clinton left the door open
 Monday for Bulgaria to join NATO in the alliance's next round of
 admitting new members in 2001.

 In talks with Bulgarian President Petar Stoyanov and Prime Minister
 Ivan Kostov, Clinton praised the Bulgarian leadership for assisting
 the alliance during the Kosovo war, a senior White House official
 said.

 Clinton made clear NATO would be looking toward southeast
 Europe for new members, the official said.

 Bulgaria would like to join 19-member alliance and is hoping it could
 do so as early as the next round in 2001. NATO has made no commitments yet.

 The White House official, who spoke on condition of anonymity, said both Stoyanov and
 Kostov told Clinton that joining NATO was "a very high priority for them."

 "They've undertaken a sweeping military reform while downsizing their military
 substantially," the official said.

 "And I think their decision to support NATO's action in Kosovo was really kind of a
 watershed for the way they think about the world."

 Bulgaria borders Yugoslavia and was one of the Balkan frontline states that supported
 NATO during the 11-week air war against Serbia last spring, letting allied jets use its air
 space despite public opposition that grew stronger when an errant NATO missile hit a
 Sofia suburb.

 Clinton told Bulgarian leaders, the official said, that "in some ways after the Kosovo conflict
 there's a more compelling case that can be made for NATO looking toward the nations of
 southeast Europe in the next wave."

 CLINTON VOWS SUPPORT TO BULGARIAN REFORMS

 Clinton, the first sitting U.S. president to visit Bulgaria, opened his visit with vow of support
 for the former communist nation seeking to reform its economy and recover from setbacks
 due to the Kosovo crisis.

 "We are committed to supporting them over the long-run -- economically, politically,
 militarily," Clinton told reporters. "I think we will be doing it for many years."

 The president's gift bag, some of which has already been delivered, includes financial aid
 through the Export-Import Bank and the Overseas Private Investment Corporation.

 On November 12 Clinton submitted to Congress a request to allow duty-free treatment for
 a number of key imports, including shoes and glassware from Bulgaria and other Balkan
 countries.

 Trade links with Serbia, a major trading partner, were disrupted during the Kosovo conflict
 and Bulgaria's economy has not yet recovered. U.S. officials estimate it cost Bulgaria $100
 million in lost trade when its main highway and Danube River route with western Europe
 through Serbia was cut.

 CLINTON TALKS ABOUT KOSOVO, RUSSIA

 Clinton was to address an open-air rally at Nevski Square later in the day. Tuesday he flies
 to Kosovo to visit U.S. troops on peacekeeping duty there, last stop on a 10-day trip to
 southern Europe.

 In Kosovo, Clinton said, he would appeal against reprisals by ethnic Albanians against
 minority Serbs.

 "I'll make a very strong statement about the importance of everyone getting over this ethnic
 hatred and going beyond it. I think it's very important that Kosovo not become, in effect,
 the mirror image of Serbia," he said.

 Clinton also said it was uncertain whether Russia would keep a commitment to seek a
 political solution to the conflict in Chechnya. "They made clear they were going to continue
 their military offensive," he said. "We'll have to see."