"In Iraq we are now projecting approximately 140,000 troops there in July," General Carter Ham, operations director of the Joint Staff, told reporters. He had earlier said that 8,000 support forces and trainers will need to stay on.

"It is, by the end of July, bigger than when we started the surge" in January 2007.

About 132,000 troops were in place when President George W. Bush ordered an increase in US forces in Iraq in a bid to quell violence and clear the way for political reconciliation among rival factions.

"There is a full expectation that further reductions will occur" in troop levels, Ham said, but it was "premature" to talk about "timing and pace" of this further drawdown.

Ham said earlier this month that support forces and trainers that went in with the surge will still be needed to back up Iraq's expanding security forces after the last of the extra combat brigades leaves.

About 8,000 support troops were deployed to Iraq as part of the surge.

General David Petraeus, the US commander in Iraq, has called for a pause in US troop reductions after July to allow time to evaluate the performance of Iraq's security forces and the impact on security of a smaller US force.

At the peak of the post-surge period, the United States had some 170,000 troops in Iraq as it fought to quell a violent insurgency following the 2003 invasion which it led to depose former dictator Saddam Hussein.

That number has since declined as gradual withdrawals have begun, and currently stands at around 158,000.

Petraeus is expected to make recommendations by April on whether further cuts can be made after the drawdown of five combat brigades -- about 20,000 troops -- is completed in July.

Defense Secretary Robert Gates said last week that Petraeus and his commanders had persuaded him a brief pause would then be needed to assess the situation.

"My hope still is that we will be able to further draw down our troops in Iraq over the course of the next 10 to 12 months," Gates said.

The continuing US presence in Iraq after five years and more than 3,000 US deaths in the country has become an emotional issue in campaigns for this year's presidential election. The two remaining Democratic candidates, Barack Obama and Hillary Clinton, have called for a swift withdrawal.

In neighboring Afghanistan, which international forces are fighting to stabilize against an insurgency in the south, the United States will raise its number of soldiers to around 32,000, Ham said.

This would be an all-time high for US troop numbers in Afghanistan, where the United States led the ousting of the hardline Taliban regime in 2002.

The boost will come from some 3,200 Marines due to be sent there in the spring, to fight alongside NATO-led troops against Taliban militias and help train Afghan security forces.

Ham also said the Pentagon wanted to reduce the length of US soldiers' tours of duty from 15 to 12 months, but would wait until the end of July to make a decision.

The new center-left government of Australia -- one of the United States' key allies -- has meanwhile confirmed it will honor an election pledge to pull 550 Australian combat troops out of southern Iraq by the middle of the year.