British prime minister Gordon Brown says an immediate review of airport security systems will be completed within the next few days.
He says the review, which was ordered in the wake of a failed attempt to blow up an American passenger plane bound for Detroit on Christmas Day, will consider the use of full-body scanners for people flying to the United States.
Umar Farouk Abdulmutallab, 23, of Nigeria, boarded the flight in Amsterdam with explosives in his underpants. He had flown from Accra in Ghana, to Lagos and then to Amsterdam.
Abdulmutallab is now in a federal prison in Michigan and has told investigators he was trained by al Qaeda in Yemen.
Mr Brown has called a summit in London on 28 January to discuss radicalisation in Yemen.
No 10 said the event had support from Washington and the European Union, and Mr Brown aimed to attract Saudi Arabia and Gulf states.
Britain is one of the biggest donors to the Yemen - Â£100 million.