President Pervez Musharraf should stand down for the sake of stability in Pakistan, a Brussels-based think-tank said in a report on the deteriorating situation following the assassination of Benazir Bhutto.

"Stability in Pakistan and its contribution to wider anti-terror efforts now require rapid transition to legitimate civilian government," International Crisis Group said in its report released on Thursday.

"This must involve the departure of Musharraf, whose continued efforts to retain power at all costs are incompatible with national reconciliation."

Crisis Group, which has been fiercely critical of Musharraf, urged the United States to use its influence to persuade the president to quit.

Pakistani officials regarded the report as unbalanced.

President George W. Bush, in an interview with Reuters, said he backed Musharraf because he had proved a strong ally in fighting terrorism and had fulfilled his pledge to step down as army chief late last year and to hold an election.

"I think that whoever wins the election is somebody with whom President Musharraf should work, and of course we will be a strong ally of Pakistan," Bush said.

Musharraf, who came to power in a coup in 1999, quit as army chief in November before being sworn in for a second five-year term as president.

But first he declared emergency rule to purge the Supreme Court of judges who appeared set to annul his re-election by the outgoing parliament.

Emergency rule was ended on December 15.

The election for a new parliament has been delayed until February 18 from January 8 in the wake of violence following the assassination of Bhutto.