* Dempsey is U.S. Army chief, commanded troops in Iraq war
* To take top U.S. military job at time of budget pressure
* Obama expected to name other top military posts Monday
By Phil Stewart
WASHINGTON, May 28 (Reuters) - Army Chief of Staff General Martin Dempsey, expected to be named the top U.S. military officer on Monday, will need to draw on his experience in and out of war zones to navigate a budget battle awaiting him in Washington.
The White House said President Barack Obama will make Pentagon personnel announcements at 10 a.m. (1400 GMT) on Monday.
U.S. officials expect that, beyond Dempsey's nomination as chairman of the military's Joint Chiefs of Staff, Obama will announce other top military posts. People familiar with the matter say former Iraq war commander General Raymond Odierno is expected to be named as Dempsey's successor as the Army's top officer.
The nomination of Dempsey, who commanded troops during the Iraq war, would be the last major change to Obama's core national security team following the president's announcement in April of new leaders for the Defense Department and the CIA. [ID:nN28281089]
The U.S. Senate must vote to confirm nominees to head the Joint Chiefs of Staff. Analysts say Dempsey is expected to face questions during the Senate confirmation process about efforts to tighten defense spending, even as the Pentagon is confronted with numerous other pressing matters.
The U.S. military is engaged in a nearly decade-old war in Afghanistan, is on track to withdraw its remaining 48,000 troops from Iraq by the end of this year, and has taken part in military operations in Libya.
In addition to the instability in the Middle East and north Africa, the United States is dealing with a Chinese military buildup, North Korean provocations and tensions with Pakistan.
"There is no part of the defense structure that, at this point in time, isn't going to have to change," said defense analyst Anthony Cordesman at the Center for Strategic and International Studies, a Washington think tank.
Asked about Dempsey's expected nomination, Cordesman described him as "a better planner, better manager, better budgeter at a time when those skills are going to be almost as important as strategy."
Republicans and Democrats are looking at defense spending reductions as a way to reduce the U.S deficit, which is running about $1.4 trillion this year. Obama announced plans in April to save about $400 billion in national security spending over the next 12 years. Some in Congress want deeper defense cuts.
Dempsey stands out among top Pentagon officials in part for his unexpected traits -- he is party crooner with a master's degree in English. But his infantry background will satisfy those in Congress who want the top U.S. military officer in a nation at war to have battlefield experience.
Dempsey commanded the 1st Armored Division in Iraq shortly after the U.S.-led invasion in 2003 and headed the effort to train Iraqi security forces from 2005 to 2007.
From 2007-2008, he was the No. 2 and then acting commander of U.S. Central Command, which oversees the wars in Iraq and Afghanistan. He also led the U.S. Army's training effort.
But even Dempsey must be surprised that, just over a month after taking over as chief of staff of the Army, he is expected to take over the post being vacated by Admiral Mike Mullen, who steps down as chairman of the Joint Chiefs of Staff on Oct. 1.
The presumptive nominee to replace Mullen had been General James Cartwright, the current vice chairman of the Joint Chiefs of Staff who was described in journalist Bob Woodward's book "Obama's Wars" as the president's favorite general.
But questions arose about Cartwright's leadership style, and neither Mullen nor outgoing Defense Secretary Robert Gates endorsed Cartwright for the job, a U.S. official told Reuters.
Defense analyst Michael O'Hanlon of the Brookings Institution think tank said he did not believe that Dempsey's short tenure as Army chief of staff made him any less prepared for the chairman's job.
"At this kind of a moment, it would a disadvantage in some ways to being seen as too closely affiliated with the Army's interests," O'Hanlon said.
One big question is whether Dempsey will assume the same prominent diplomatic role in relations with Pakistan's military as his predecessor. Mullen, who was in Islamabad this week, served as the main interlocutor with Pakistan's powerful army chief General Ashfaq Kayani. [ID:nL3E7GR0C4]
Critics of U.S. strategy toward Pakistan say that despite Mullen's efforts and billions in U.S. aid, Islamabad is a half-hearted ally at best in the fight against militants.
The May 2 U.S. raid in Pakistan that killed al Qaeda leader Osama bin Laden has heightened tensions between Washington and Islamabad.
Dempsey and Kayani studied together in the 1980s at the U.S. Army Command and General Staff College at Fort Leavenworth, Kansas, and met last month when the U.S. general was in Pakistan, an aide said.
(Additional reporting by Jeff Mason; Editing by Will Dunham)