In the deadliest attack on foreign troops since August, six US soldiers were killed in Afghanistan on Monday when a suicide attacker rammed an explosives-laden motorcycle into a joint NATO-Afghan patrol.
The soldiers were targeted as they moved through a village near Bagram Airfield, the largest US military facility in Afghanistan, NATO and Afghan officials said.
"We're deeply saddened by this loss," said Shoffner.
A US official confirmed all NATO troops killed were American. Two wounded were also US soldiers and the other was Afghan.
The Taliban claimed responsibility for the attack.
In New York, Police Commissioner William Bratton said on Monday that a New York City police detective, Joseph Lemm, was one of the six Americans killed in the attack.
Lemm was a 15-year-old veteran of the New York Police Department and worked in the Bronx Warrant Squad.
Bratton says Lemm served in the US National Guard and, while a member of the police force, he had been deployed twice to Afghanistan and once to Iraq.
He leaves behind a wife and three children.
Blasts rock Kabul
Later on Monday, a rocket attack barrage rocked the capital Kabul with at least three loud explosions.
Two rockets landed near Kabul's diplomatic district, a police source told Al Jazeera.
A third rocket hit an area near Kabul airport, the source added. No casualties have so far been reported.
READ MORE: Fierce fight for Helmand as Afghan Taliban gains ground
The Taliban has claimed responsibility for the attack.
"We will continue to target foreign forces until they leave our country [Afghanistan]," Zabihullah Mujahid, the Taliban spokesperson told Al Jazeera.
The violence comes as a southern district in Helmand province fell to the Taliban after days of heavy fighting, officials told Al Jazeera.
The Taliban has stepped up attacks and has made territorial gains since NATO forces reduced troop levels and handed over security responsibilities to the Afghan National Army a year ago.
