BAGHDAD" Iraq's embattled Prime Minister Nouri al-Maliki is taking his struggle to keep his post to the courts after announcing he will file a legal complaint on Monday against the country's newly elected president.

 

The deadlock over a new government has plunged Iraq into a political crisis at a time it is fighting a land grab by Islamic State of Iraq and Greater Syria (ISIS) militants. The blitz offensive by the Al-Qaeda breakaway group has become Iraq's worst crisis since the U.S. troops withdrew from the country in 2011.

 

Maliki has resisted calls for his resignation, and the political infighting could hamper efforts to stem advances by the Sunni militants who have seized a large swath of northern and western Iraq in recent weeks.

 

In a televised speech after midnight Sunday, Maliki declared he would file a legal complaint against the new president, Fouad Massoum, for committing "a clear constitutional violation."

 

The prime minister said the president, who was elected by parliament, is obstructing Maliki's re-election. He said Massoum had carried out "a coup against the constitution and the political process."

 

Maliki, whose Shiite-dominated bloc won the most parliament seats in April elections, accused Massoum of neglecting to name a prime minister from the country's largest parliamentary faction by Sunday's deadline.

 

The late-night speech was Maliki's first since U.S. forces launched airstrikes and humanitarian airdrops in Iraq last week. A parliament session scheduled for Monday to discuss the nomination of the new prime minister was postponed until Aug. 19.

 

Meanwhile, Iraqi special forces loyal to Maliki were deployed at Baghdad's main intersections Monday, police officials said. Two of the capital's main streets, which are popular locations for pro and anti-government rallies, were partially closed Monday.

 

The government also enforced a heightened security alert across the city, said the officials, who spoke on condition of anonymity because they were not authorized to talk to media.

 

It was not immediately clear when Maliki would submit his complaint, presumably in a Baghdad court Monday.

 

But his action raised concerns abroad.

 

In Washington, State Department spokeswoman Jen Psaki said the United States rejected any effort to use "coercion or manipulation" in the process of choosing a new Iraqi leader.

 

The U.N. special representative for Iraq, Nickolay Mladenov, called on Iraqis to "exercise restraint at this dangerous time" adding that Iraq's "special forces should refrain from actions that may be seen as interference in matters related to the democratic transfer of political authority."

 

The U.S. airstrikes have reinvigorated Iraqi Kurdish forces battling the Islamic State in northern and western Iraq. Kurdish forces retook two towns from the Sunni militants Sunday, achieving one of their first victories after weeks of retreating, a senior Kurdish military official said.

 

Kurdish peshmerga fighters were able to push the militants out of the villages of Makhmour and al-Gweir, some 45 kilometers from the Kurdish capital of Irbil, peshmerga Brig. Gen. Shirko Fatih said.

 

The United States launched a fourth round of airstrikes Sunday against militant vehicles and mortars firing on Irbil as part of efforts to blunt the militants' advance and protect American personnel in and around the Kurdish capital.

 

U.S. warplanes and drones have also attacked militants firing on minority Yezidis around Sinjar, which is in the far west of the country near the Syrian border.

 

President Barack Obama warned Americans Saturday that the new campaign to bring security in Iraq required military and political changes and "is going to be a long-term project."

 

Obama said Iraqi security forces needed to revamp to effectively mount an offensive, which requires a government in Baghdad that the Iraqi military and people have confidence in.

 

Obama said Iraq needed a prime minister - an indication that suggests he's written off the legitimacy of the incumbent, Maliki.

 

Critics say the Shiite Maliki contributed to the crisis by monopolizing power and pursuing a sectarian agenda that alienated the country's Sunni and Kurdish minorities.

 

A week ago, Maliki ordered the Iraqi air force to support Kurdish forces against the militants, in a rare instance of cooperation between Baghdad and the Kurdish regional government, which have for years been locked in disputes over oil and territory.

 

All the while, the country's humanitarian crisis is growing, with some 200,000 Iraqis recently joining the 1.5 million people already displaced from violence this year. British officials estimated Saturday that 50,000 to 150,000 people could be trapped on Sinjar Mountain, where they fled to escape the Islamic extremists, only to become stranded there with few supplies.