TOYAKO, Japan, July 9 (UPI) -- The United States is against a schedule to withdraw troops from Iraq, the White House said, despite Iraqi officials wanting a plan as part of a security pact.

"We have always been opposed, and remain so, to an arbitrary withdrawal date," White House spokesman Dana Perino said Wednesday in Japan before the Group of Eight summit ended. "We believe that, as we've said before, that any actual troop withdrawal schedule needs to be based on conditions on the ground."

On Tuesday, Iraqi leaders said Baghdad wouldn't accept a security agreement being negotiated with the United States unless it included a timetable for withdrawing foreign troops. A government spokesman said any withdrawal schedule would depend on ground conditions.

"We want a sovereign Iraq to be able to take on more of its own security, more responsibility and we have been able to talk to them about some aspirational time frames for some of those activities," Perino said.

The statements from Iraq "we believe reflect the recent positive developments in Iraq," she said.

The U.N. mandate providing the legal basis for U.S. combat troops in Iraq expires at the end of 2008.