• Pledge follows acknowledgment of difficulty of closing facility • More than 200 detainees remain at Guantánamo Bay

President-elect Barack Obama is to issue an order to close the Guantánamo detention centre in his first week in office, according to his advisers.

Obama, who takes over the presidency next Tuesday, will make closure one of his first decisions, two of his advisers told the AP news agency.

The pledge comes only the day after Obama appeared to row back from campaign promises by saying closure was more complicated than he had realised and it would be a challenge to do so in his first 100 days in office.

Guantánamo has become a touchstone for the new administration. Democrats and liberal lawyers, as well as European governments, have repeatedly called for its closure, seeing it as an affront to human rights. Some of the detainees have been tortured.

There were about 700 detainees after a sweep of countries throughout the world as part of George Bush's "war on terror". While most have been released, more than 200 are still held.

There is no consensus yet on what to do with them. Some will be released, and some could be transferred to other countries, while the remainder could face trial on the US mainland.

Five human rights groups today urged Obama to stop a war crimes trial at Guantanamo of a Canadian, Omar Khadr, now 22, who is accused of killing a US soldier in Afghanistan when he was 15.