Prime Minister Tony Blair last night led a memorial service in New York for the Britons missing in the World Trade Centre rubble - and praised the worldwide solidarity for the victims of the terrorists.

At a service at St Thomas Church, Mr Blair joined UN Secretary General Kofi Annan and former US President Bill Clinton in prayers for the dead, missing and injured, especially those from Britain.

With his wife Cherie at his side and accompanied by the British Ambassador to Washington, Sir Christopher Meyer, Mr Blair delivered a reading about death and loss.

The service was the first formal expression of grief for 200 to 300 British citizens missing after the terrorist attack.

Mr Blair, before delivering his reading, said: "There is no reading and there are no words that truly bring comfort to those missing their loved ones today.

"After the terrible events of last week, there is shock and disbelief and there is anger round the whole of the world.

"There is the most profound solidarity, there is the determination to build hope up. There is the surging human spirit.

"We wanted to be here today to offer our support and sympathy to the families of the loved ones.

"The bonds between our two countries, so strong for so long, are even stronger today."

Mr Blair then delivered a reading from Thornton Wilder's The Bridge of San Luis Rey, which said: "There is a land of the living and there is a land of the dead and the bridge is love. The only survival, the only meaning."

Mr Blair added: "It is about a tragedy that took place when a bridge collapsed across a gorge and killed five people.

"These words were said by someone who knew the victim."

As he finished his reading, a fire engine could be heard speeding down Fifth Avenue outside the church, one of the largest episcopal churches in New York.

Almost 1,000 people gathered at the church - among them at least 80 relatives who had come from Britain in the last few days to find out the fate of their loved one.

After the service, Mr Blair left for Washington for talks with President Bush as the US pushed ahead with military preparations to strike at Afghanistan, which is sheltering terrorist mastermind Osama bin Laden.

Afghan leaders had suggested that bin Laden could be asked voluntarily to leave the country.

But the White House said bluntly that the proposal by a council of Islamic clerics for dealing with the man it regards as the "prime suspect" behind the US terror atrocities "does not meet America's requirements".

The Pentagon announced that the US Army was ready to mount "sustained land combat operations" as part of President Bush's "war" on international terrorism.

White House press secretary Ari Fleischer said the US stood by its demands for the handover of bin Laden to "responsible authorities" and for the closure of terrorist camps in Afghanistan.

"This is about much more than any one man being allowed to leave - presumably from one safe harbour to another," he said.