WASHINGTON, May 6: The top Democrat in the US House of Representatives on Thursday accused Defence Secretary Donald Rumsfeld of a cover-up in the scandal over abused Iraqi prisoners and said he should resign.

"I think that Mr Rumsfeld should step down," House Minority Leader Nancy Pelosi of California told reporters. "Mr. Rumsfeld has been engaged in a cover-up from the start on this issue," she said.

Sen Tom Harkin, an Iowa Democrat, echoed her call. "For the good of our country, the safety of our troops and our image around the globe, Secretary Rumsfeld should resign. If he does not resign forthwith, the president should fire him," he said.

Top Republicans in the House dismissed the resignation calls, and most lawmakers said it was too early to fix blame for the abuses. Mr Rumsfeld was to testify on Friday before the Senate and the House's armed services committees in an appearance at which some lawmakers said his job could be in the balance.

Asked if Mr Rumsfeld should resign, Sen Edward Kennedy, a Massachusetts Democrat, said: "I think it will be determined on his testimony. We ought to listen to him."

"I think the overall issues, obviously, are the issues of accountability and responsibility and the extent of all of this," Mr Kennedy said. "Is this the tip of the iceberg or the whole thing?"

A Senate Republican aide said Mr Rumsfeld must "give the performance of his life", and show contrition. "He needs to have full disclosure of the facts, no parsing of words or displaying the usual convoluted testimony that the Senate Armed Services Committee has been accustomed to," the Republican aide said.

House Majority leader Tom Delay, a Texas Republican, and several other House Republicans defended Mr Rumsfeld and accused the Democrats of trying to politicize the war. "Calling for Secretary Rumsfeld's resignation is as bad a signal as saying the war in unwinnable," DeLay told reporters. -Reuters