The top US commander in Iraq said Thursday that the situation there is "exceedingly complex and very tough," and predicted things may get worse before getting better.

Gen. David Petraeus told reporters at the Pentagon that success in Iraq will depend on progress made by the Iraqi government.

Petraeus also claimed that the US-Iraqi security crackdown in Baghdad has reduced sectarian attacks significantly in recent months.

However, he noted there will be an increase in such attacks if coalition forces pulled out of the Iraqi capital in the coming months.

Calling his job "the most complex and challenging I have ever seen," Petraeus avoided a direct question on how long US troops will stay in Iraq.

He spoke as the US Senate began debating legislation passed Wednesday by the House of Representatives that includes a non-binding provision to begin pulling US troops out of Iraq by October.

On Wednesday, Petraeus spent three hours in closed meetings with members of Congress.

Lawmakers who spoke after the meetings mostly repeated their known positions on the war.

Democratic Senator Carl Levin, who heads the Senate Armed Services Committee, said he did not think Petraeus had changed any minds during the sessions.

(Xinhua News Agency April 27, 2007)