The Iraq war is to blame for high gas prices as its cost has weakened the dollar and driven oil speculation, Sen. Claire McCaskillClaire McCaskillA guide to the committees: Senate Juan Williams: Senate GOP begins to push Trump away Dem senator: I may face 2018 primary from Tea Party-esque progressives MORE (D-Mo.), a national co-chair of Barack ObamaBarack ObamaPoll: Majority of voters oppose border wall, ObamaCare repeal Muslim White House staffer quits, slamming Trump’s travel ban French fans to Obama: Run for president here MORE's presidential campaign, said today.

"We cannot economically afford to keep borrowing two to three billion dollars a week from China," McCaskill said on MSNBC. "That's why gas prices are so high. People are speculating in commodities because nobody wants to go near our dollar. We cannot--it is unsustainable to continue to prop up, in the middle of a civil war, an Iraqi government that will not step up and do what they need to do."

McCaskill appeared on MSNBC this afternoon to discuss Obama's planned trip to Iraq and Afghanistan. McCaskill is a national co-chair of Obama's campaign. When host Monica Novotny pressed McCaskill on Obama's plan to withdraw from Iraq despite recent security gains, McCaskill pushed back by saying the war's cost is unsustainable.

"If you can't leave Iraq when it's stable and you can't leave Iraq when it's not stable, that means that we're stuck with George Bush and John McCainJohn McCainHannity apologizes for sharing 'inaccurate' story about McCain McCain spokeswoman: Hannity should 'correct the record' after 'fake news' tweet CNN to host town hall featuring John McCain, Lindsey Graham MORE--we can never leave Iraq," McCaskill said. See the video below.