British Foreign Secretary David Miliband said on Saturday the bombing of an Islamabad hotel was a "disgraceful" attack which reinforces Britain's resolve to fight violent extremism with Pakistan.
"This latest bombing attack in Islamabad is yet another shocking and disgraceful attack without justification," Miliband said.
"Such an indiscriminate and brutal act of terror deserves the condemnation of the entire international community.
"We continue to stand shoulder-to-shoulder with the government of Pakistan against the violent extremists who have no answers but only offer death and mayhem.
"This horrific attack reinforces our shared determination to tackle violent extremism."
A suicide bomber detonated a truck packed with explosives at the heavily-guarded Marriott Hotel in the Pakistani capital, killing at least 60 people.
The Foreign Office said four British citizens were injured in the bombing.
It said they were receiving treatment in hospital and their condition was unknown.
New Pakistani President Asif Ali Zardari held talks with British Prime Minister Gordon Brown in London this week.