Washington  - US President Barack Obama said Tuesday that his administration is ushering in a "new era" of diplomacy, vowing to strive for Middle East peace and assuring the nation that he will not back down in the war on terrorism.

In his first major address before Congress, Obama said he will strengthen alliances and seek new ones throughout the world while emphasizing the importance of negotiations to resolve differences.

"We are showing the world that a new era of engagement has begun. For we know that America cannot meet the threats of this century alone, but the world cannot meet them without America," Obama said.

"We cannot shun the negotiating table, nor ignore the foes or forces that could do us harm. We are instead called to move forward with the sense of confidence and candor that serious times demand."

Obama's speech largely focused on the ongoing economic crisis and touched only briefly on foreign policy and national security issues, as the White House continues reviewing a long list of international priorities including the conflicts in Iraq and Afghanistan.

"We are now carefully reviewing our policies in both wars, and I will soon announce a way forward in Iraq that leaves Iraq to its people and responsibly ends this war," said Obama, who campaigned on pulling all combat troops out of the country within 16 months of taking office.

Obama said he is forging "a new and comprehensive strategy" for the fight in Afghanistan that will address safe havens in Pakistan used by the Taliban and al-Qaeda to launch cross-border raids against US, NATO and Afghan forces.

"I will not allow terrorists to plot against the American people from safe havens half a world away," Obama said.

Last week, he ordered 17,000 more US soldiers into Afghanistan, and thousands more could arrive within a year.

Obama intends to draw down the US presence in Iraq and shift the effort to Afghanistan, which has grown increasingly unstable amid a rapidly deteriorating security environment.

His biggest national security move in the early days of his presidency has been ordering the closure of the notorious detention centre for terrorism suspects in Guantanamo Bay, Cuba. Obama said that shuttering the prison that has been the target of torture allegations is intended to restore America's moral leadership.

"Living our values doesn't make us weaker, it makes us safer, and it makes us stronger," Obama said. "And that is why I can stand here tonight and say without exception or equivocation that the United States of America does not torture."

Obama said he will seek "swift and certain justice for captured terrorists," and has set up a task force to determine what to do with the remaining 245 cases at Guantanamo.

The 43rd president did not specifically mention the international efforts to prevent Iran from acquiring nuclear weapons and persuade North Korea to abandon its atomic programme, but pledged to meet the challenges posed by nuclear proliferation. (dpa)