The White House discounted the Iraqi announcement.
The consequences of the Iraqi announcement will begin to unfold on Thursday.
The Iraqi announcement coincides with an annual meeting here of the world's leading financial ministers and central bankers to discuss global economic matters.
In London, the Foreign Office said only that it was aware of the Iraqi announcement.
The Iraqi announcement was broadcast on the state-run radio and monitored by Western correspondents in Cyprus.
The Iraqi announcement caught the Bush Administration by surprise.
The Iraqi announcement gave no numbers on the captives.
Crude oil futures prices fell to the lowest level since Nov. 22 on Tuesday after the Iraqi announcement.
The Iraqi announcement of an air raid on gulf shipping today was the second of its kind this week.
An Administration official said Mr. Bush was not signaling a new attitude toward the Iraqi announcement.