Barack Obama is to set out his plan to pull most US combat troops out of Iraq by August 2010 when he makes his first visit as president to a military base on Friday, his spokesman said. US news media reported Friday that Obama told congressional leaders at a private White House meeting on Thursday that he intends to pull US combat troops out by August 2010. Obama also reportedly told the top legislators that he plans to keep between 35,000 and 50,000 US support troops in Iraq.