The presidential office released a statement on Friday saying its additional troops would help “the rapid reconstruction of post-war Iraq and the settlement of peace in the region”.
"(South Korea) will make a decision on the scale, timing and type of troops later after taking consideration of the US request as well as public opinion and military capability."
Since May about 700 South Korean medical and engineering troops have been working out of a US base in the Iraqi town of Nassariya.
Replacements for the initial contingent began flying out this week.
Last month, the United States asked Roh's government to send combat troops to help stabilise Iraq. South Korean media have said Washington wants Seoul to commit to sending about 5000 men by the end of this month.
South Korean President Roh Moo
-hyun faces tough balancing act
But Roh faces a tough political decision on the troops request, having to weigh strong public opposition to the Iraq war against Seoul's desire to shore up its military alliance with Washington.
Roh said in an interview with Reuters on Friday that it was vital to take thorough soundings on the public's view. Latest opinion polls suggest a majority would support committing combat troops with UN backing.
"The government will send an additional survey team to Iraq, if needed in the process of finalising type and formation of troops to be deployed," said Ra Jong-il, a national security advisor for Roh.
A South Korean fact-finding team sent to Iraq last month to study security said on its return last week the picture was mixed. It did not commit itself on whether combat troops should go.
Separately, the government said in a statement it would contribute another $200 million for Iraqi reconstruction over the next four years on top of $60 million earmarked earlier this year.