Cabinet approval of a plan to dispatch Self-Defense Forces units to Iraq will probably be delayed until next week at the earliest, in the wake of the fatal ambush Saturday of two Japanese diplomats.

The government had considered endorsing the plan at a Cabinet meeting this week.

The government "must pay grave consideration to such an incident" in making a final decision on when to dispatch troops, Chief Cabinet Secretary Yasuo Fukuda said Monday. At the same time, however, he reiterated that Japan will not back down from its plan to send troops to Iraq.

"There is no change in our stance of cooperating with the international community and doing everything we can for the reconstruction of Iraq," Fukuda said. "We are making preparations" for mapping out the dispatch plan, he said.

Although the Diet is not currently in session, Prime Minister Junichiro Koizumi said the government would be willing to engage in deliberations on the matter at a Diet committee meeting, in line with the demands of opposition parties.

Naoto Kan, leader of the Democratic Party of Japan, renewed his opposition toward an SDF dispatch, criticizing Koizumi's decision to support the U.S. war, along with his "promise" to Washington that SDF units would be sent to the Mideast country.

Koizumi "had an optimistic assumption that the security condition would improve, but he made a mistake," Kan told reporters. "We must thoroughly debate the issue at the Diet."

Koizumi told reporters later in the day that he is aware there are "cautious opinions," even within the ruling parties. "There are various opinions, and I will make a decision after considering different opinions," he said.

Fukuda said a government fact-finding team that returned from the southern Iraqi city of Samawah last week would report to him by Tuesday. Samawah is considered safer than other parts of Iraq and is a candidate site for SDF troops to engage in humanitarian and reconstruction assistance.

This report and the Foreign Ministry's investigation into the weekend ambush would be the basis for making a decision on the dispatch, Fukuda said. "We will consider all of (these) matters to make a comprehensive decision."

The two diplomats -- 45-year-old Katsuhiko Oku and 30-year-old Masamori Inoue -- were gunned down Saturday while traveling by car to Tikrit in northern Iraq. Their Iraqi driver was also slain.

A senior government official said the dispatch plan remained intact in spite of the killings.

"But the question is when, in what size and where the SDF units should be sent," the official said.

"We have to see public opinions and voices within the ruling parties. It looks like it'll take some time" before the Cabinet approves the basic dispatch plan, the official said.

Investigation ordered

Staff report

Prime Minister Junichiro Koizumi instructed Foreign Minister Yoriko Kawaguchi on Monday to launch a thorough investigation into Saturday's ambush of two Japanese diplomats in Iraq, as conflicting accounts of the incident were being reported.

A spokesman for the U.S. military said the pair were shot to death as they stopped to buy food and drinks at a stand, but local police reportedly said bullet holes from an automatic rifle were found on the left side of their vehicle, indicating they may have been fired on by a passing car.

Government officials said no conclusion has been reached on how the killings occurred.

"There seem to be different views of (how) the attack (took place)," Koizumi told reporters after meeting the foreign minister at the Prime Minister's Official Residence. "I have told (Kawaguchi) to thoroughly look into the situation."

Meanwhile, Kawaguchi will cancel her three-day trip to Jakarta scheduled to begin Tuesday due to the deaths of the two envoys, ministry officials said.