The Illinois senator has not been to the war-torn country since before President George Bush increased U.S. troop levels to quell sectarian violence, the St. Louis Post-Dispatch reported Saturday.
Republican National Committee Chairman Mike Duncan said Obama's lack of first-hand knowledge means he "has no credibility discussing the future of Iraq."
On the political organization's Web site, a live streamer lists the days, hours, minutes and seconds since Obama's only trip to Iraq.
Sen John McCain, R-Ariz., the Republican presidential candidate, also has pointed out Obama has not been to Iraq in almost 2 1/2 years.
Susan Rice, senior foreign policy adviser to the Obama campaign and a former assistant U.S. secretary of state, said GOP claims that Obama lacks credibility on the war are "complete garbage."
Obama is considering going to Iraq soon, a campaign spokesman said.
Brookings Institution military expert Michael O'Hanlon, who advised 2004 Democratic presidential nominee John Kerry, says politicians need to see the post-surge changes in Iraq firsthand.
"I think it's a no-brainer," O'Hanlon said, adding Obama would be "remiss" as a candidate if he didn't visit Iraq soon.