President Bush's top military and diplomatic leaders in Iraq will testify in the Senate on April 8.

Gen. David Petraeus and U.S. Ambassador to Iraq Ryan Crocker will sit before the Senate Armed Services at a 9:30 a.m. hearing. They are expected to move to the Senate Foreign Relations Committee in the afternoon.

As Multi-National Forces in Iraq commander, Petraeus is the top U.S. military official in Iraq and has been in charge of directing Bush's troop surge since he announced it in January 2007. Crocker is the top U.S. diplomatic officer in Baghdad.

Petraeus and Crocker — who will also give testimony on the other side of the Capitol before the respective House committees — will detail the highly anticipated report to Congress on progress in Iraq. It is the first time they have appeared before lawmakers since their widely anticipated report in September.

After their report last fall, Bush announced staged drawdowns of troop levels citing a decrease in insurgent and terrorist activity throughout the summer following the addition of about 30,000 U.S. troops. Over the course of the following months, Bush called for the removal of five U.S. brigades and other troop movements designed to bring troop levels back down to pre-surge levels.

However, Bush has not indicated yet he will continue the drawdown past the pre-surge levels of approximately 130,000 troops. He said Thursday he is waiting on Petraeus and Crocker's report to make his final determination.

Since taking control in Congress in 2006, Democrats have tried — and failed — dozens of times to impose a date-certain for withdrawal from Iraq. Whatever Bush's decision is, it is certain to become an issue on the presidential trail as well.

Both Democrats Barack Obama and Hillary Clinton have promised to begin bringing troops home soon after they would take office, while Republican presumptive nominee John McCain has vowed to continue to remain in Iraq until the war is won.