Mr. Abadi served as the head of parliament’s finance committee, a political advisor to the prime minister and minister of communications.

State television showed footage of the president shaking hands with Mr. Abadi and telling him: “I hope you will be successful in forming a broader-based government.”

U.S. Secretary of State John Kerry said Monday that the formation of an Iraqi government was critical for stability of that country and urged Nouri al-Maliki not to stir up political tensions further.

Kerry told reporters in Sydney ahead of an annual Australia-United States Ministerial Consultations: “The government formation process is critical in terms of sustaining stability and calm in Iraq, and our hope is that Mr. Maliki will not stir those waters.”

“One thing all Iraqis need to know is that there will be little international support of any kind whatsoever for anything that deviates from the legitimate constitution process that is in place and being worked on now.”

Nouri al-Maliki, serving in a caretaker capacity since an inconclusive election in April, is under pressure to step aside from Kurdish, Sunni and some elements of Iraq’s Shi’ite community.

He went on Iraqi television on Sunday night to accuse Iraq’s Kurdish President Fuad Masum of violating the constitution by failing to meet a deadline to ask Iraq’s biggest political bloc to nominate a prime minister and form a government.

Washington swiftly responded to Maliki’s address with two state department officials expressing their support for Masum – who was appointed president on July 24.

“The United States fully supports Fuad Masum in his role as guarantor of the Iraqi constitution,” State Department spokeswoman Marie Harf said, echoing a response on Twitter from a leading US diplomat for the region, Brett McGurk.

Special forces loyal to Maliki deployed in strategic areas of Baghdad Sunday night after he delivered a tough speech indicating he would not cave in to pressure to drop a bid for a third term.