British troops will begin withdrawing from Iraq in March and will mostly be gone by June, the Ministry of Defense said Wednesday. Britain has about 4,000 troops in southern Iraq. It expects to begin withdrawing them after regional elections planned for next month, the ministry said, confirming reports in British media. The number of troops will fall to 300-400 by midyear, the reports said. A US brigade will replace the British force at Basra airport, ministry officials told reporters from British media in a briefing Tuesday. The ministry confirmed reports of the briefing to The Associated Press. A new US-Iraqi security pact calls for 150,000 American troops to be withdrawn from Iraq in two stages by the end of 2011. Iraq's Parliament has yet to ratify a new status of forces agreement with Britain to allow British troops to stay into next year.