Britain has given a strong welcome to the United Nations-brokered power-sharing deal reached between Afghan groups in Bonn.

The prime minister, Tony Blair, hailed the agreement as a "truly remarkable achievement".

"It is the result of the real courage shown by the parties at the table, the outstanding work of the UN in facilitating the talks and the united approach adopted by the international community," he said. "Afghanistan today has the opportunity of a new beginning, to build a future in which everyone will have a say, no matter what their tribal background or gender.

"There is still an enormous amount left to do on the three tracks of the campaign, military, humanitarian, diplomatic, but the Bonn agreement is the foundation on which a stable and prosperous future for Afghanistan can be established."

The Bonn accord, announced on Wednesday after a marathon talks session, will lead to the creation of a 30-member interim Cabinet headed by Hamid Karzai.

Karzai is a moderate Muslim whose fighters are part of the push to oust the Taliban from their last stronghold in Kandahar.

The cabinet will be made up of all the Afghan groups with two posts going to women.

The Northern Alliance has many of the key positions - including defence.

The cabinet will be the first phase in normalising post-Taliban rule in the country before a broad-based government representing the range of Afghanistan's ethnic groups and regions takes over.

It will run the country for six months until a tribal council, or loya jirga, announces the next stage.

Foreign secretary Jack Straw welcomed the deal saying progress had been achieved more quickly than anybody could have imagined.

"The signing this morning of the agreement on Afghanistan's future is a significant achievement. I pay tribute to the Afghan leaders - men and women - who have grasped this opportunity to begin to rebuild their country," he said.

"This is a victory for the coalition against terrorism. A stable Afghanistan, with a broad-based government, is as important to our own security as it is to the Afghan people. This really is one world."

For the Conservatives shadow foreign secretary Michael Ancram the deal gave hope for long-term peace.

"This is an agreement made by the people of Afghanistan for the people of Afghanistan. It constitutes a major breakthrough after 20 years of war. As a result there is understandably a tremendous sense of hope for the future.

"What is important now is that this transitional government proves itself to be genuinely representative of the whole of Afghanistan, and resolute in ensuring that Afghanistan will never again be used as a haven for international terrorism," he said.