TOKYO (Reuters) -- A shocked Japan debated on Monday whether to send troops to help rebuild Iraq after two Japanese diplomats were killed there, and a poll showed most were opposed to the dispatch at least until security improves.

Prime Minister Junichiro Koizumi reiterated that Japan's commitment to help rebuild Iraq would not waver but he gave no clue as to when the dispatch might occur. The main opposition Democratic Party said it was staunchly against deploying troops.

"There is no change in our stance," Koizumi told reporters. "We must not be daunted by the intention of terrorists to halt the reconstruction effort and cause confusion."

The diplomats, who were traveling by road to a reconstruction conference in Saddam Hussein's home town of Tikrit, were the first Japanese to be killed in Iraq since the U.S.-led invasion.

They were among a dozen people from four nations killed in weekend attacks, sparking new concern among Washington's allies about the risks of getting involved in post-war Iraq.

Japanese media reacted with anger and sadness to the deaths but were sharply divided over whether Koizumi should proceed with his plans to send troops.

The plan was already on hold after a bomb attack killed 19 Italians in southern Iraq last month.

"Why were these people, who loved Iraq and worked without regard for the danger, killed? The incident is all too painful. Whatever the reason, we cannot forgive the perpetrators," the liberal ***Asahi Shimbun*** newspaper said in an editorial.

The ***Asahi*** said it was time for Koizumi to admit that conditions in Iraq did not meet the requirements of a law enacted in July to allow Japan to deploy non-combat troops there.

Japan has passed a special law to enable it to send troops to Iraq but, in line with the nation's pacifist constitution, they can be sent only to "non-combat zones" to take part in reconstruction and humanitarian work.