At least 25 people died in Kabul during Tuesday's 20-hour-long attack by insurgents on the US embassy, Nato headquarters and police buildings.
The US ambassador to Afghanistan, Ryan Crocker, dismissed the attack as "harassment" and "not a very big deal".
The dead included 11 civilians, among them children, along with at least four police and 10 insurgents.
The Nato commander in Kabul, Gen John Allen, admitted the insurgents had scored a propaganda victory.
"The attacks beginning yesterday afternoon were designed to derail transition... the insurgent attack didn't succeed, it failed," he told a news conference in Kabul.
"I'll grant that they did get an IO [Information Operations] win on this," he added.
International forces have begun handing over responsibility for security to the Afghan authorities in a transition which is scheduled for completion in 2014.
"This really is not a very big deal," said Ambassador Crocker. About six or seven rockets landed within the embassy perimeter fence, he said.
"That isn't [the] Tet [offensive], that's harassment," he went on.
The 1968 Tet offensive was the turning point in the Vietnam war which eventually led to the pull-out of US forces.
Tuesday's attack, the most complex in Kabul to date, comes as US and other foreign forces begin to withdraw their troops.
During the attack, at least six gunmen took over a multi-storey building overlooking Kabul's heavily protected diplomatic quarter.
It began at about 13:30 local time (09:00 GMT) on Tuesday when a car packed with insurgents was stopped at a checkpoint at Abdul Haq Square about 1km (0.6 mile) from the US embassy.
Witnesses said there were several large explosions and the insurgents entered a nearby nine-storey building under construction.
From there, several militants opened fire on the embassy complex with machine guns, rocket-propelled grenades and possibly a mortar.
In the end, Afghan forces had to work their way up through the building, exchanging fire with all the militants on the floors above until the last of the gunmen was killed, 20 hours later.
Suicide bombers were also sent to other targets in the city. One was heading for the airport when he was killed by Afghan security forces.
The Taliban said it was behind the attack, although Afghan officials blamed the Haqqani network, an insurgent group linked to the Taliban and al-Qaeda but which operates independently.
The US embassy said none of its staff members was among the casualties, but Nato has confirmed six International Security Assistance Force (Isaf) personnel were injured.
US Army helicopters and an Afghan army MI-35 attack helicopter were involved in the operation.
Intelligence officials have been going through the lower floors, gathering evidence about the way the assault was planned and carried out.
Officials told the BBC the attackers had left behind explosives and burkas in a van on the site and that each of the attacker had been carrying hand grenades, pistols and an army knife. Their suicide vests also contained ball-bearings, said the officials.
"If this is the best they can do, I find both their lack of ability and capacity and the ability of Afghan forces to respond to it actually encouraging in this whole transition process," Mr Crocker said.
The ambassador said he also believed the attacks to have been carried out by the Haqqani network.
The attackers are believed to have spent a number of days accumulating weapons in the unfinished tower block. The BBC's Bilal Sarwary in Kabul says officials think some of them may have been working as labourers on the building site for several weeks.
Haroun Mir, director of the Kabul-based Afghanistan Centre for Research and Policy Studies, said it was the first time that four groups of militants had attacked in four different places.
"This is new as previously we had one or maximum two attacks. The Haqqani network has the full support of al-Qaeda and has the capacity to execute sophisticated attacks. It is the only group with this capacity."
Afghan President Hamid Karzai condemned the attacks, saying they would not deter Afghan forces from taking full responsibility for security by the time international combat troops withdraw.
"By carrying out such attacks terrorists cannot stop the transition of security from international to Afghan forces," he said in a statement.
Earlier this year, Isaf handed over responsibility for security in seven areas of Afghanistan, including two provinces.