Washington: US soldiers heading to war this summer are likely to see their tours shortened from 15 months to 12 months, even if troop cuts in Iraq are suspended in July as expected, the Army's top general said on Tuesday.

General George Casey said that while his forces are strained by nearly seven years at war, the Army can maintain 15 combat brigades in battle for at least a couple of months after July while military commanders assess the situation in Iraq.

"Fifteen deployed brigades, for us, is sustainable for a bit longer, certainly enough to cover what I would think the length of this pause might be," said Casey, the Army's chief of staff.

Defence Secretary Robert Gates and General David Petraeus, the top US commander in Iraq, have both said they favour a suspension in troop cuts after July to assess security gains before more forces leave the country.

While neither Casey nor Petraeus will say how long that suspension may last, Casey says it likely will not hamper his move to 12-month tours.

"A month or two [pause] wouldn't have a significant impact on what we're talking about doing," he told a small group of reporters in his Pentagon office.

Casey also said for the first time publicly that his goal is to eventually shorten war deployments to nine months, with soldiers getting 18 months at home between tours.

One of several key factors that would enable him to do that, he said, would be to have just 10 Army brigades deployed to war - nine fewer than there are in battle right now in Iraq.

Currently soldiers are serving 15-month tours, returning home for a year, then heading back out for another deployment.

During much of last year, there were 20 combat brigades in Iraq and two in Afghanistan; 20 of those were Army units, two were Marines.

In December one Army unit came home from Iraq and was not replaced, bringing the total to 19. Over the next five months, five more brigades will leave Iraq and four will not be replaced, reducing the total to 15.

A brigade is roughly 3,500 personnel.

During much of last year, there were 20 combat brigades in Iraq and 2 in Afghanistan; 20 of those were Army units, 2 Marines.