The US President George W Bush has accepted the resignations of four of his Cabinet members, including Secretary of State Colin Powell.
It is understood that Mr Powell will stay in the position until a replacement is named.
Mr Powell was often seen as representing more moderate views on foreign policy in the Bush administration.
Explaining his decision, Mr Powell said he had always told President Bush that he would only serve one term.
The other members leaving the Cabinet are Energy Secretary Spencer Abraham, Agriculture Secretary Ann Veneman, and Education Secretary Rod Paige.
Powell due to visit West Bank
Earlier, the Palestinian Foreign Minister, Nabil Shaath, told reporters that Mr Powell was expected to hold talks with the new Palestinian leadership on a visit to the West Bank next week.
Mr Shaath said Mr Powell would hold discussions with the new Palestine Liberation Organisation Chairman, Mahmoud Abbas, and the Prime Minister, Ahmed Qurei, during his visit.