BAGHDAD — Iraq’s president on Monday formally nominated a candidate to replace Prime Minister Nouri Kamal Al-Maliki. The step broke a months-long political deadlock, but it also seemed to take Iraq into uncharted territory, as Maliki gave no signal that he was willing to relinquish power.



As the country faces the threat of Islamic State fighters in the north, Al-Maliki's stand raises fear of more infighting.



The nomination of Haider Al-Abadi, who is a member of Maliki’s Shiite Islamist Dawa Party, came hours after a dramatic late-night television appearance in which a defiant Maliki challenged President Fuad Masoum and threatened legal action for not choosing him as the nominee.



As he spoke in the middle of the night, extra security forces, including special forces units loyal to Maliki, as well as tanks, locked down the fortified Green Zone of government buildings and took up positions around the city. Soldiers manned numerous checkpoints on Monday and were numerous in the Green Zone, and the atmosphere in the capital was tense.



The ceremony came hours after the embattled al-Maliki delivered a surprise speech at midnight accusing Masoum of blocking his reappointment as prime minister and carrying out "a coup against the constitution and the political process."



Maliki upped the ante further when his Dawa Party issued a televised statement rejecting Al-Abadi's nomination, saying he did not have the support of the party.



"Al-Abadi represents only himself," said party spokesman Khalaf Abdul-Samad surrounded by stone-faced party members, including Al-Maliki.



Al-Abadi, who pledged to form a government to "protect the Iraqi people," was nominated for the post by the Iraqi National Alliance, a coalition of Shiite parties that includes Al-Maliki's.



The powerful Shiite cleric, Muqtada Al-Sadr, whose movement controls dozens of seats in parliament, expressed his support for Al-Abadi's nomination, describing it as the "first sign" the country was headed back to safety.



"I think that this nomination will be an important start in order to end the crisis that the people are undergoing such as security and service problems," he said in a statement.



Al-Abadi is a British-educated lawmaker with a background in electrical engineering and a member of Al-Maliki's Dawa party. He has been closely involved in previous governments.



Abadi now has 30 days in which to form a government that offers meaningful positions to Iraq’s main minority factions, Sunnis and Kurds.



The UN special representative for Iraq, Nickolay Mladenov, said Iraq's "special forces should refrain from actions that may be seen as interference in matters related to the democratic transfer of political authority."



Britain has expressed support for Al-Abadi's nomination and Vice President Joe Biden called the Masoum to express the US support and commend him on the nomination.



Meanwhile, senior US officials said the Obama administration, which launched airdrops and airstrikes last week to support Kurdish and Iraqi forces battling militants from the Islamic State group, has begun directly providing weapons to the Kurdish peshmerga forces who have started to make gains against the Al-Qaeda breakaway group that controls much of the north. — Agencies