The Japanese Government is defending its decision to send troops to Iraq before the foreign affairs committee in parliament.
By Jonathan Head
BBC correspondent in Tokyo
Despite the capture of deposed Iraqi leader Saddam Hussein, the opposition parties in Japan are still demanding that the prime minister reverse his decision, saying it contravenes Japan's pacifist constitution.
Defending his policy in front of a parliamentary foreign affairs committee, the Defence Minister, Shigeru Ishiba, said the government would still monitor the security situation closely before deciding when to send the troops.
But good news from Iraq is also good news for Japan's embattled prime minister these days.
Tokyo's plan to send troops has provoked strong public protests
Junichiro Koizumi's determination to stand by his promise of troops for Iraq has provoked street protests and strong criticism from the opposition. So there was relief, but caution too, in the government's reaction to the news of Saddam Hussein's capture.
The first Japanese transport aircraft are expected to arrive in Kuwait next month, but ground troops probably will not be in Iraq before February.
A matter of interpretation
Japan's constitution restricts its self-defence force to just that - self-defence - which means the troops, while armed, can only do humanitarian and reconstruction work; they are barred from combat.
That has forced the government into some delicate explanations.
If Japanese forces shoot back after being attacked, that would not, said Mr Ishiba, be defined as combat.
The prime minister initially said Japanese aircraft would not carry weapons for allied forces.
Now he says they can if they are carrying allied troops at the same time.
No Japanese soldier has been killed in action since World War II and even senior government officials believe the death of just one soldier in Iraq or the killing of a civilian by Japanese troops could cost Mr Koizumi his job.