BAGHDAD (AP) — Democratic presidential candidate Barack Obama’s visit to Iraq for talks with commanders of a war he long opposed follows the prime minister’s apparent endorsement of his troop withdrawal plan and a shift by the White House away from refusing to discuss that option.

Obama has called for withdrawing U.S. troops at the rate of one or two brigades a month, ending combat operations within 16 months of becoming president. He favors leaving behind a residual force to protect U.S. personnel, train Iraqi security forces and counter attacks by al-Qaida.

The Illinois senator, challenged at every turn on the Iraq issue by Republicans, including presidential rival Sen. John McCain, was expected to arrive in the country amid the controversy over comments by Prime Minister Nouri al-Maliki that were supportive of Obama’s 16-month timetable.