Nato pledged help to reinforce security for the Athens Olympics

The decision - on the day the alliance officially welcomed seven new members - comes three weeks after the Madrid bombings that killed 191 people.

Speaking in Brussels, US Secretary of State Colin Powell urged Nato to consider a new role in Iraq after a local government takes power in July.

But the German and French ministers immediately rejected his call.

We think Nato is simply not the right place where a decision should be prepared Michel Barnier French Foreign Minister

Germany's Foreign Minister, Joschka Fischer, said the alliance was already "overstretched" with its missions in the Balkans, Afghanistan and its efforts to fight terrorism.

His new French counterpart, Michel Barnier, said the issue was "not topical".

"We think Nato is simply not the right place where a decision should be prepared or taken concerning the situation in Iraq after 1 July," he said in remarks quoted by Reuters news agency.

Mr Powell had suggested Nato could take over a sector in Iraq or train Iraqi security forces.

But Nato has been insisting on a new UN Security Council resolution before deploying its troops in Iraq.

New measures

Nato foreign ministers also issued a statement after their meeting in Brussels, outlining new measures to increase co-operation in the fight against terrorism.

Their pledges include:

• more sharing of intelligence

• reinforcing security for this summer's Athens Olympics and European football championships in Portugal

• co-ordinating Nato assets to deal with nuclear, chemical and biological attacks

• enhanced support if a Nato member suffers a terror attack.

On Friday morning, a ceremony was held at Nato headquarters to welcome seven former communist countries as members of the 55-year-old alliance.

The flags of Bulgaria, Estonia, Latvia, Lithuania, Romania, Slovakia and Slovenia were raised for the first time at the Nato headquarters in Brussels.

The three Baltic republics, Estonia, Latvia and Lithuania, were once part of the Soviet Union, the very power against which Nato was created.