U.S. Vice President Joe Biden said Sunday the U.S. combat troops in Iraq are on schedule to withdraw by the end of August, and would not be delayed by lengthy power-sharing negotiations in the Iraqi government.

Speaking to ABC's "This Week" program, Biden said the Iraqi transition government is "in place that's working. Iraqi security is being provided by the Iraqis."

The U.S. forces last year have pulled out of Iraqi cities and are working to formally end combat operations by Sept. 1 of this year, cutting the U.S. military force from just under 90,000 to 50, 000. A full withdrawal is also in sight at the end of 2011. However, Iraq's political blocs are still discussing the formation of a new government, months after the March 7 elections.

Biden said he is confident the withdrawal won't affect the physical stability of Iraq.

Twin suicide bombings targeting Awakening Council group members in west of Baghdad were reported Sunday, killing at least 43. Recent spate of bombings and waves of violence are still ravaging Iraqi cities, including the capital, more than four months after the country held its landmark parliamentary elections on March 7, raising fears of a return to