South Korea's acting president has put his nation on high alert, saying the country is a potential terrorist target.
Acting South Korean President Goh Kun is ordering stepped up security following the terrorist bombings in Spain that killed more than 200 people.
Presidential spokesman Kim Duck-Bong quotes Mr. Goh as saying that countries with troops in Iraq have become primary targets for attack.
South Korea has approved plans to dispatch three thousand troops next month to northern Iraq. Hundreds of the country's army engineers and medics are already in southern Iraq engaged in reconstruction and humanitarian work.
Mr. Goh, who is also prime minister, became the acting head of state after the impeachment of President Roh Moo-hyun last Friday. He says the troop deployment will go ahead.
That would make the South Korean contingent the third largest foreign military force in Iraq after the United States and Britain.
Some analysts, such as security expert Hong Kwan-hee, say they now believe the terrorism threat is as real as the long-standing one from communist North Korea.
Mr. Hong said,"Both threats together is possible. And (they are) threats to our country's national security."
U.S. President George Bush on Tuesday called on American allies not to give in to pressure from the al Qaida terrorist group and withdraw troops from Iraq.
Spain's incoming Socialist prime minister has said he will pull Spanish troops out of Iraq following the train bombings in Madrid unless they come under UN command.
In Japan, Prime Minister Junichiro Koizumi says keeping troops in place is the only reasonable policy to follow.
Members of Japan's Self-Defense Forces are in southern Iraq on reconstruction and humanitarian missions.
Mr. Koizumi is facing increasing pressure from the political opposition which argues that the one thousand strong Japanese force in the Persian Gulf could make Japan a terrorist target as well.
Government spokesman Yasuo Fukuda says it is important for Japan to do its utmost to help Iraq stand on its own feet.
Meanwhile, security in and around Tokyo subway and rail stations has been visibly increased since the Madrid attack.