IRBIL, Iraq - The president of Iraq's self-rule Kurdish region demanded Wednesday that Shiite leaders agree on sharing power with their political opponents by September or else the Kurds could consider breaking away from Baghdad.

The warning by Kurdish President Massoud Barzani in an Associated Press interview underscores that Shiite domination in Iraq's government is reviving secession dreams that the now-departed U.S. military had tried to contain.

"What threatens the unity of Iraq is dictatorship and authoritarian rule," he said in a 45-minute interview in his sprawling office outside of Irbil, the capital of the Kurdish region he leads in northern Iraq. "If Iraq heads toward a democratic state, then there will be no trouble. But if Iraq heads toward a dictatorial state, then we will not be able to live with dictatorship."

He called it a "very dangerous political crisis in the country" and said the impasse must be broken by September, when voters in the Kurdish region may consider a referendum for a state independent of Iraq.

Prime Minister Nouri al-Maliki's media adviser, Ali al-Moussawi, declined immediate comment.

The specter of a divided Iraq has been discussed - and dismissed by many - for months. Barzani said Wednesday that he was still committed to negotiating a compromise before promoting secession. But he insisted it would be an option if the government logjam continued much longer.

Iraq expert Ramzy Mardini, with the Institute for the Study of War in Washington, said Barzani's comments likely were aimed more at getting Maliki to bend to Kurds on some positions instead of containing a real threat to secede.

He noted that Kurds were years from having enough oil and gas infrastructure to produce the resources necessary to support an independent state.

The Kurdish region is politically autonomous, although it does receive a share of the nation's $100 billion annual budget. On Wednesday, Barzani signaled he was impatient with requests by President Obama and Vice President Biden for the Kurds to work with the Maliki government.

"They reiterated they support a federal, democratic, pluralistic, united Iraq," Barzani said. "And I reassured them that certainly if Iraq is democratic, federal, and pluralistic, it will be united."