The country’s Independent Election Commission has been slow in releasing partial results from the Aug. 20 presidential vote, while accusations of fraud have mounted. The United Nations-backed Electoral Complaints Commission has said the number of complaints that could “materially affect” the outcome had soared to 270.
Videos of possible fraud have been posted on the Internet, and Mr. Abdullah and other challengers have made complaints about cheating.
The accusations, along with low turnout in the south because of Taliban threats of violence, could strip the vote of legitimacy in Afghan eyes. Final results are to come in late September.
The lengthy election process has added to strains in relations between the United States and Afghanistan, which had already cooled since the Obama administration took office.
Meanwhile, Britain’s prime minister, Gordon Brown, paid a surprise visit Saturday to British troops in southern Afghanistan, promising more help to cope with the Taliban insurgents who have inflicted casualties on the embattled force and undercut support in Britain for the war.
Mr. Brown, speaking at the British base in Lashkar Gah, pledged to provide more equipment to help overcome roadside bombs, a major threat to NATO forces.
A British marine was killed by a bomb in Helmand on Saturday, the Defense Ministry said in London. And, Reuters reported, an American serviceman was killed by a roadside bomb in the east, NATO-led forces said in a statement that gave no further details.
Last week, British troops cleared 337 roadside bombs from some of the most dangerous roads in Helmand Province, a main focus in the recent fighting.
“Let me pay tribute to the courage, bravery, professionalism and patriotism of our forces,” Mr. Brown told the troops. “This has been a most difficult summer in Afghanistan, because the Taliban have tried to prevent elections taking place.”
He added, “I think our forces have shown extraordinary courage during this period.”
Mr. Brown also called for speeding up the elled for speeding up the effort to train about 50,000 additional Afghan troops, which would bring the overall level trained to around 135,000.
The prime minister arrived with Air Chief Marshal Sir Jock Stirrup, chief of the British defense staff, and met with senior commanders including the top United States officer, Gen. Stanley A. McChrystal.
More than 200 British soldiers have been killed in Afghanistan since the war began in 2001 — more than Britain lost in the Iraq conflict. Many in Britain believe the mission is too open-ended, and its goals too vague.
Mr. Brown’s visit came a day after Britain replaced its top army official, Gen. David Richards, a former commander of NATO forces in Afghanistan. He succeeded Gen. Sir Richard Dannatt, who was appointed in 2006 and frequently clashed with lawmakers over defense spending, particularly relating to delays in providing helicopters.
General Richards, regarded as politically savvy, was able to build close relationships with Mr. Karzai and his ministers while leading NATO troops.
British officials said that they recognized the need for better-armored vehicles and more helicopters and that they would get them here as soon as possible.
As NATO commander, General Richards was a prominent backer of a controversial peace plan in the southern Afghan town of Musa Qala under which NATO, Afghan and Taliban soldiers were not allowed in the town.
