The US president has rebuked Spain's new prime minister for going ahead with his election promise to withdraw troops from the coalition in Iraq.
Reasons for the Honduran move were not immediately clear
George W Bush voiced regret at the "abrupt Spanish action" in a five-minute phone call to Jose Luis Rodriguez Zapatero, the White House said.
Mr Bush warned against giving "false comfort to terrorists" as Spain sought to reassure its allies.
The president of Honduras has ordered his 370-strong contingent home too.
President Ricardo Maduro announced he was withdrawing his troops "in the shortest possible time".
Mr Maduro said he had consulted with "the members of the coalition and other friendly countries".
Honduran troops had been due to leave by 1 July before Monday's announcement.
The White House has announced that John Negroponte, the US envoy to the UN, is to play a key role in Iraq.
Mr Negroponte, a familiar figure from the deliberations of the UN Security Council before the war in Iraq, will serve as US ambassador to Baghdad if his appointment is approved by the US Senate.
The current US envoy, Paul Bremer, is due to step down as administrator after the coalition hands over power to an Iraqi administration as scheduled on 30 June.
A range of measures to end the military stand-off in the city of Falluja after more than two weeks have been announced by the coalition, including shortening the curfew and allowing unfettered humanitarian access to residents.
Monday saw new outbreaks of violence with a TV station funded by the coalition reporting that US troops had shot dead a journalist and his driver in Samarra, north of Baghdad.
The Spanish Socialists' new Foreign Minister, Miguel Angel Moratinos, has set off on a diplomatic shuttle tour to reassure Spanish allies in Iraq that they will not be left in the lurch.
The country's 1,300 soldiers currently play a key role in the country, especially in the flashpoint Shia holy city of Najaf.
MAIN FOREIGN TROOPS IN IRAQ
Defence Minister Jose Bono said the withdrawal would take less than two months and explained that 190 soldiers dispatched to Iraq on Monday were going to facilitate the safe and the swift exit of the Spanish contingent.
The Honduran forces, whose withdrawal was announced late on Monday, are serving with the Spanish contingent in Najaf.
Mr Bush's spokesman, Scott McClellan, told reporters that the president had "stressed the importance of carefully considering future actions to avoid giving false comfort to terrorists or enemies of freedom in Iraq".
Foreign Minister Moratinos denied Spain was washing its hands of the situation in Iraq but that is how the move to withdraw the troops is being seen by the Bush administration, says the BBC's Justin Webb.
Our correspondent says there is a widespread feeling in the US that the Spanish government has made a serious error of judgement and allowed itself to look as if its policy was dictated by terrorism.
And, unusually, the Bush administration rebuke was backed in full by Democratic party presidential challenger Senator John Kerry, our correspondent notes.