Northern Ireland political leaders are expected to visit Washington soon to discuss a deadlock in implementing the Good Friday peace accords, amid reports denied by the White House that U.S. President Bill Clinton has grown "frustrated" with a lack of progress.

David Trimble, leader of the Ulster Unionist Party, is to visit Washington on February 21 and meet with U.S. National Security Adviser Sandy Berger, White House spokesman David Leavy told reporters at the daily White House briefing on February 17.

Leaders of Sinn Fein, the political ally of the Irish Republican Army, are also likely to travel to Washington "in the near future," he said.

"I'm sure they'll talk about where we are in the process," Leavy said of the Berger meeting with Trimble, whose Ulster Unionists are the main Protestant rival to Sinn Fein. He said it appeared Trimble had requested the meeting.

He said there was no firm date for a visit from leaders of Sinn Fein, a prominent party among Northern Ireland's Roman Catholic minority.

Sinn Fein President Gerry Adams traditionally visits Washington on St. Patrick's Day, March 17, Leavy said.

He said the United States wanted to discuss "creative" ways to resolve the deadlock over the IRA's refusal to disarm.

"There have been some creative positions put forward and those positions to be debated and looked at and we hopefully can move forward," Leavy said.

The dispute over disarmament caused Britain last week to suspend a Protestant-Catholic power-sharing government that had been set up in December under terms of the 1998 Good Friday peace accords.

Leavy rejected a report in the Financial Times that Clinton was growing frustrated with setbacks in the peace process and that the president believed the IRA bore much of the responsibility.

"There is absolutely no truth to those reports," Leavy said.

"He (Clinton) is realistic. They've come a long way. We're at a bump in the road but we're hopeful that with some intense effort we can get it done," he said.

On Wednesday Clinton told a news conference he viewed it as positive that the IRA had given no indication it would resort to violence following the suspension of the power-sharing government.