Sen. Jesse Helms is predicting an "overwhelmingly positive" Senate vote to extend NATO membership to three former Soviet bloc nations: Poland, Hungary and the Czech Republic.

But some of his colleagues will also try to get the Senate to impose a temporary moratorium on expanding NATO beyond that. A lead-ing proposal, to be offered by Sen. John Warner, R-Va., would put a three-year freeze on new memberships.The Senate Foreign Relations Committee, which Helms leads, voted 16-2 Tuesday to approve the three-nation expansion. It will bring the membership of NATO to 19 nations next year. A two-thirds vote of the Senate is required to put the extension into force, but supporters predicted they had the votes.

"It appears that Senate approval of this resolution will occur on an overwhelmingly positive vote, which will be an obvious vote of confidence in the democracies of Eastern Europe," Helms, R-N.C., said.

President Clinton welcomed the committee's "strong endorsement" of his administration's push to expand NATO by three countries. "By adding these countries as newest allies, we will make NATO stronger, Europe more stable and American more secure," he said.

Critics of the resolution contended an expanded NATO could entangle the United States in a series of Bosnia-style peacekeeping missions.

Voting against it were Sens. John Ashcroft, R-Mo., and Paul Wellstone, D-Minn.

Ashcroft, a possible 2000 presidential contender, said he did not oppose the expansion in itself but believed "there should be some clarification of what the long-term mission is."

NATO "keeps redefining itself," he said.