WASHINGTON // Barack Obama, the US president, yesterday welcomed David Cameron, the British prime minister, to the White House for a visit that has been overshadowed by this week's massacre of 16 Afghan civilians - mostly women and children - by a US soldier.
Mr Obama told reporters after their meeting that the "tragic events of recent days are a reminder" that the Afghanistan war continues to be a dangerous mission.
But he insisted, "we're going to complete this mission, and we're going to do it responsibly".
Mr Cameron echoed Mr Obama's commitment, but added that he saw international troops to be in the "final phases of our military mission".
"We will not give up on this mission, because Afghanistan must never again be a safe haven for Al Qaeda to launch attacks against us," he said.
Analysts say Sunday's massacre in the southern province of Kandahar, the Taliban heartland, was unlikely to change the planned pullout of foreign troops in 2014 or affect the November US presidential election.
Mr Cameron and Mr Obama also focused on Iran and its nuclear ambitions as well as the mounting crisis in Syria, where about 10,000 people have died in a year-long uprising to topple President Bashar Al Assad, according to the UN. Mr Cameron yesterday described the Syrian regime as "bloody, brutal and broken".
Mr Obama said Iran had to abide by its international obligations "or face the consequences". Both leaders want Iran to allow international inspections of Iran's nuclear programme by the UN's nuclear watchdog.
But neither support any Israeli military strike on Iran's nuclear facilities, which Israel's leaders have consistently threatened. And which the United States itself has not ruled out as a last resort.
In a joint opinion piece in the Washington Post published on Tuesday, the two leaders wrote that there was "time and space to pursue a diplomatic solution" with Iran.
But the war in Afghanistan dominated discussions as well as the following press conference.
Sunday's massacre - in which a US soldier, said to be acting alone, killed 16 Afghan villagers in the middle of the night - is the latest in a series of incidents, including US troops burning Qurans and video of US troops urinating on dead Taliban, that has pushed relations to a low after a decade of war.
Last week, six British troops were killed in a roadside bombing, the largest loss of life in a single incident Britain has suffered in Afghanistan since 2006.
That incident followed national riots over the burning by US troops of Qurans near Bagram, the main US airbase in the country.
Dozens of Afghans were killed in the nationwide protests and six US soldiers were shot dead by Afghan colleagues as part of the backlash.
Pressure is growing for the US to pull out of a war almost two thirds of Americans say they no longer support. An ABC News/Washington Post poll released on Monday but conducted before the shootings found 60 per cent of Americans think it has not been worth fighting.
In the survey, 54 per cent of respondents said the US should pull out now, without waiting to train Afghan soldiers and police to take over.
The Nato-led force is set to withdraw its troops at the end of 2014 after a transition of security responsibilities to Afghan forces.
In a country with few functioning institutions and an army and police force battling to become professional, it would be a recipe for chaos and few US politicians consider that a serious option, - especially during an election year.
Sunday's massacre might bring a speeded up transition schedule, said Marvin Weinbaum, an Afghanistan specialist with the Washington-based Middle East Institute.
But there will be no fundamental change in strategy.
"Rather than the drawdown being back loaded, it will be front loaded, which means the pace of the drawdown will be stepped up," he said.