The most recent deaths, coming just before Christmas and a few months after Obama's decision to extend the longest war in US history, are likely to stick with the President.
His press secretary issued a statement: "The US condemns this cowardly attack on members of the US and Afghan forces, and we remain committed to supporting the Afghan people and their Government."
The Taliban attack killed six service members near Kabul, US officials said, in the latest sign of deepening violence across Afghanistan and the risks facing Obama's plan to leave the most intense fighting to local forces.
US military officials said the attack, the most deadly insurgent assault on American forces in at least three years, took place a few kilometres from Bagram, when a motorbike rigged with explosives detonated and hit a group of US troops attending a meeting with local figures.
The attack comes as the Afghan Government struggles to beat back a series of large-scale Taliban offensives and contain a nascent campaign by militants linked to Isis (Islamic State).
The Pentagon said the blast wounded two other US service members and a contractor. Three Afghan police officials were also injured.
In recent months, Afghan security forces have been overwhelmed by a series of militant offensives revealing the Government's vulnerability when it doesn't have substantial foreign firepower to support it.
It took local forces several weeks to reclaim Kunduz, a major city that was overrun by Taliban forces. This month, militants have mounted a deadly siege on an airport in the southern province of Kandahar and launched a suicide assault on a diplomatic complex in Kabul.
Yesterday, the group also said it had taken Sangin, a district of Helmand province that once symbolised the success of Obama's decision to send additional US forces in 2010.Washington Post - Bloomberg