British troops will begin pulling out of Iraq in March and, by next summer, there will be just 400 British personnel in the country, a senior defense source said Wednesday.

The troops will make way for several thousand American soldiers who are to move into the British base at Basra airport, in the south of the country. The SAS squadrons that are currently operating from Baghdad on counter-terrorist missions will also be withdrawn and are expected to be transferred to Afghanistan to fight the Taliban.

The precise timing of the first homecomings will depend on the arrival of an American two-star military headquarters, which will be set up at the airport base northwest of Basra city.

Plans are now well advanced for the withdrawal of Britain's 4,100 troops even though a "status of forces" agreement has yet to be reached with the Iraqi Government.

In March a few units will withdraw, marking the beginning of the end of the British campaign, codenamed Operation Telic. The speed of withdrawal will quicken as the U.S. troops begin to deploy in southern Iraq.

A brigade of between 4,000 and 5,000 U.S. troops is expected to set up home at the airport, which has been the principle location for Britain's military presence in Iraq over the past five years.

The U.S. forces will extend their reach south of Baghdad, partly in order to guard supply routes from Kuwait. The British job of “mentoring” the Iraq Army's 14th Division in Basra is expected to be completed within three months.

Under present planning, the reduced British force of about 400 will include the Service personnel who are based in Baghdad, with the exception of the SAS squadrons. Some British personnel will remain in the south to continue training the Iraqi Navy at Umm Qasr port, after a specific request for them to do so by the Baghdad Government.

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