President Barack Obama puts his pen away after signing an executive order to close the Guantanamo Bay detention centre during a ceremony in the Oval Office at the White House on Thursday. Standing behind Obama are Vice-President Joe Biden and retired military officers. (Saul Loeb/AFP/Getty Images)U.S. President Barack Obama signed an executive order on Thursday to close the controversial detention centre at Guantanamo Bay in Cuba within a year, saying the move would restore his country's "moral high ground" in the battle against terrorism.

"We intend to win this fight, and we're going to win it on our terms," Obama said at a signing ceremony in the Oval Office at the White House in Washington, D.C.

Just two days after his inauguration, Obama also signed a separate order to put an immediate end to harsh interrogation techniques against detainees.

"I can say, without exception or without equivocation, that America will not torture," Obama declared later in the day during an address to State Department staff.

The orders come a day after a U.S. military judge granted a 120-day adjournment for all war-crimes cases before the military commission at Guantanamo Bay, including that of Canadian Omar Khadr, at the request of the new president.

It was not immediately clear if the cases will resume at the end of the 120 days. There are currently 14 pending cases referred to trial at Guantanamo.

Cannon welcomes Obama's decision

A closure of the prison facility could pave the way for the Toronto-born Omar Khadr, who is accused of killing a U.S. soldier in Afghanistan, to be repatriated to Canada, potentially to undergo a judicial process here.

In this sketch by a courtroom artist, Canadian defendant Omar Khadr attends a hearing Monday at the U.S. military commissions court for war crimes at the U.S. naval base in Guantanamo Bay, Cuba. (Janet Hamlin/Pool/Associated Press)

Obama's decision to shut down Guantanamo is "welcome news," Canadian Foreign Affairs Minister Lawrence Cannon told Radio-Canada on Thursday, but said 22-year-old Khadr has been accused of a serious crime and that his case must follow due judicial process.

His message echoed that of the Prime Minister's Office, which on Wednesday downplayed suggestions that it is reconsidering the government's long-held position not to intervene in the case.

Thursday's orders fulfil one of Obama's campaign promises and break from the widely condemned security policies of his predecessor, George W. Bush.

The facility, set up by the Bush administration in the wake of the Sept. 11, 2001, attacks, had been the subject of scorn and outrage for human rights groups and legal observers. Critics had decried the detention of terrorism suspects for years without trial or charges, as well as the use of coercive and secretive interrogation techniques on detainees.

An estimated 245 men are being held at the U.S. naval base.

Task force could change interrogation rules for CIA

Obama also created a task force that would have 30 days to recommend policies on handling terrorism suspects who are detained in the future and decide where those detainees should be housed.

"If there are detainees who cannot be transferred or prosecuted, the review will examine the lawful options for dealing with them," the order states.

As of now, all U.S. personnel are required to follow the U.S. Army Field Manual while interrogating detainees. The manual explicitly prohibits threats, coercion, physical abuse and waterboarding, a technique that creates the sensation of drowning and has been termed a form of torture by critics.

"The message that we are sending around the world is that the United States intends to prosecute the ongoing struggle against violence and terrorism, and we are going to do so vigilantly," Obama said after signing the orders.

"We are going to do so effectively and we are going to do so in a manner that is consistent with our values and our ideals."

But Obama's order also includes a potential amendment to interrogation guidelines for the Central Intelligence Agency. The task force, to be led by the attorney general, will conduct a review of the Army Field Manual interrogation guidelines "to determine whether different or additional guidance is necessary for the CIA."

White House press secretary Robert Gibbs wouldn't get into specifics when asked by reporters later Thursday whether that amendment represented a potential contradiction.

"I know that as it relates to going forward, that everybody's under the Army Field Manual," Gibbs said.

"The commission has been tasked with studying any number of different scenarios relating to detainees and interrogation and I think what's best is to let that happen and see what happens when they come back."

The CIA has admitted to waterboarding at least two detainees at Guantanamo, including Khalid Sheikh Muhammed, the alleged architect of the Sept. 11 attacks.

Susan Crawford, the Pentagon official overseeing the military commission process, recently acknowledged the United States tortured an inmate at the facility.

In an interview published last week in the Washington Post, Crawford disclosed that the United States tortured a Saudi detainee named Mohammed al-Qahtani in 2002, subjecting him to isolation, extreme cold temperatures that endangered his life and sleep deprivation. She was the first senior Bush administration official to make such a statement.

Questions loom over Khadr's fate

Khadr's legal team has also said evidence presented against him was coerced through aggressive interrogation, as well as torture.

Khadr, who is the only Western citizen remaining in detention at the U.S. naval base in Cuba, is accused of killing an American soldier in Afghanistan in July 2002, when he was 15.

Security experts predict that Obama's decision means Khadr could be returned to Canada this year. If he is repatriated, however, it's unlikely the government will seek to prosecute him, according to a former Foreign Affairs official.

"I mean you look at that evidence, there is a very large question mark about whether or not Mr. Khadr was responsible for these initial charges," said Gar Pardy, the former director general of consular affairs for the Department of Foreign Affairs.

Others said while it's theoretically possible to try Khadr under Canada's anti-terrorism act, it would be a remote possibility.

"The evidence is too tainted. This is a child [who] was captured at the age of 15," said Wesley Wark, a security issues and intelligence expert at the Munk Centre for International Studies in Toronto.

"I just can't see the government, any government — Conservative, Liberal — of the day deciding that this was a likely prosecution."

In an interview on Wednesday, Kory Teneycke, Prime Minister Stephen Harper's spokesman, told CBC News that the Conservative government's position on the Khadr case hasn't changed from that of previous Liberal governments that were in power when Khadr was first detained in 2002.

"Our position is that the determination of his guilt or innocence on those charges needs to take place in a court of some fashion, and that we will wait for the outcome of a judicial process before looking at what the other options are," Teneycke said.

Khadr is accused of:

• Murder in violation of the law of war.
• Attempted murder in violation of the law of war.
• Conspiracy.
• Providing material support for terrorism.
• Spying.

Decision ends 'sad episode': EU

Obama's decision to close the detention centre was immediately hailed by former inmates, human-rights advocates and government officials around the world.

The European Commission said in a statement it "has been very pleased that one of the first actions of Mr. Obama has been to turn the page on this sad episode of Guantanamo."

Jomaa al-Dosari, 35, from the eastern Saudi Arabian city of Dammam, was released from Guantanamo about a year ago, after six years.

"When I heard the news I said to myself, 'I wish Obama was elected years ago. Guantanamo would not have happened,' " he said.

With files from the Associated Press