The ceasefire will begin at midnight Hanoi time on Saturday, 27 January, monitored by an international force made up of troops from Canada, Poland, Hungary and Indonesia.

President Nixon's speech from the Oval office at the White House was broadcast on national radio and television.

He said: "Throughout the years of negotiations, we have insisted on peace with honour, I set forth the goals that we considered essential for peace with honour.

"In the settlement that has now been agreed to, all the conditions that I laid down then have been met."

The conditions include the release of prisoners of war within 60 days and all American forces to be withdrawn within the same time period.

An international conference will be held within 30 days, probably in Vienna, to guarantee the peace.

American forces have been involved in the conflict in Vietnam for more than a decade. In 1967, there were 500,000 American troops deployed in Vietnam.

For the people of South Vietnam, the president had this message: "By your courage, by your sacrifice, you have won the precious right to determine your own future and you have developed the strength to defend that right.

"We look forward to working with you in future, friends in peace as we have been allies in war."

To the leaders of North Vietnam, the president said: "As we have ended the war through negotiations, let us now build a peace of reconciliation.

"For our part, we are prepared to make a major effort to help achieve that goal, but just as reciprocity was needed to end the war, so, too, will it be needed to build and strengthen the peace."