Bush's security chief resigns

Tom Ridge resigned as state governor to join the cabinet

US Homeland Security Secretary Tom Ridge has announced his resignation from President George Bush's cabinet.

He said he was stepping down to pay "more attention to personal matters".

Mr Ridge was appointed by President Bush to be the first White House homeland security adviser within weeks of the 11 September hijacks.

He said he would remain at the head of the 180,000-strong department until 1 February next year, unless the Senate confirms his successor earlier.

He was charged by Mr Bush with rethinking security arrangements and preventing further attacks on US territory.

There will always be more to do, but today, America is significantly stronger and safer than ever before Tom Ridge Grand organiser bows out

"I will always be grateful for his call to service," Mr Ridge said on Tuesday.

"There will always be more to do, but today, America is significantly stronger and safer than ever before," he said.

Mr Ridge was responsible for raising the national security level to "orange alert" on six occasions because of fears of an imminent terrorist attack.

He has always fiercely denied accusations that some alerts were timed to boost support for Mr Bush.

'Extraordinary organisation'

The former Pennsylvania governor had been widely expected to leave his position.

He is the latest cabinet member to announce his resignation since Mr Bush was re-elected on 2 November.

Secretary of State Colin Powell, Attorney General John Ashcroft and Commerce Secretary Donald Evans have all stepped down in the last few weeks.

The AP news agency quoted an email circulated by Mr Ridge to staff in his department, praising it as "an extraordinary organisation that each day contributes to keeping America safe and free".

Profile: Tom Ridge

He said he was privileged to work with people "who go to work every day dedicated to making our country better and more secure".

Mr Ridge was elected to Congress six times before becoming Pennsylvania governor in 1995.

He gave up that post in October 2001, when Mr Bush asked him to oversee the merger of 22 government agencies into the homeland security department.

Several people have been touted as possible successors to Mr Ridge.

They include Frances Townsend, the president's adviser on homeland security, and Asa Hutchinson, the undersecretary for homeland security.

Other names in circulation are Mitt Romney, the governor of Massachusetts, and Mike Leavitt, who was governor of Utah during the Salt Lake City Winter Olympics in 2002.