KANSAS CITY, Mo., Aug. 21 — Senator Barack Obama said Tuesday that even if the military escalation in Iraq was showing limited signs of progress, efforts to stabilize the country had been a “complete failure” and American troops should not be entangled in the sectarian strife.

“No military surge, no matter how brilliantly performed, can succeed without political reconciliation and a surge of diplomacy in Iraq and the region,” Mr. Obama said. “Iraq’s leaders are not reconciling. They are not achieving political benchmarks.”

Mr. Obama, of Illinois, addressed the national convention of the Veterans of Foreign Wars one day after Senator Hillary Rodham Clinton, one of his leading rivals for the Democratic presidential nomination in 2008, addressed the group. In her speech, Mrs. Clinton, of New York, said elements of the Bush administration’s troop buildup in Iraq appeared to be working, particularly in Al Anbar Province.

After Mr. Obama made his remarks, he was asked in a brief interview with reporters whether he agreed with that assessment.