The Home and Defence Secretaries visited Islamabad today amid heightened security after a blast at a UN office.
Five people were killed and several injured as a suicide bomber blew himself up in the lobby of the World Food Program in the Pakistani capital, police and witnesses said.
Bob Ainsworth and Alan Johnson were due to meet several ministers in the city as part of an initiative to highlight the key role Pakistan plays in handling terror in the UK.
A British Embassy spokesman said the pair would continue their visit as scheduled.
He said: "I'm not prepared to say where they are staying, but it is safe to say they were not affected."
Mr Johnson said the border between Afghanistan and Pakistan were the areas where "three-quarters of terror attacks are generated".
He added: "We have a very good relationship with Pakistan - they are the second most important country besides the US in our counter-terrorism partnership.
"It gives us a role to play, not just in the UK, but to help Pakistan protect itself."
The WFP is distributing food to poor Pakistanis, including those in the northwest who have been displaced or affected by a recent Pakistan army offensive against militants in the Swat Valley.