The United States has started supplying weapons directly to Kurdish forces fighting Islamic militants in northern Iraq, Associated Press, or AP, reported Monday, citing U.S. government officials. The Kurdish peshmerga are fighting back the Islamic State, formerly known as ISIS, which has taken over large parts of Iraq's west and north.

The announcement came from senior officials in President Barack Obama's government, which had previously said that Washington is only selling arms to the Iraqi administration. Although the officials did not confirm the agency responsible for supplying arms to the peshmerga, who had suffered a setback until last week, an official reportedly said that it is not the Pentagon. The senior official also said that the Obama administration is close to getting an approval from the Pentagon to arm the Kurds.

The additional assistance from Washington comes even as the U.S. government authorized air strikes on the Islamic militants in Iraq last week, AP reported. On Friday, Obama had said that Iraq's forces will need time to retake all the land ceded to the militants, and until then, the U.S. will continue with airstrikes to protect its personnel there and the minority Yazidi community, which is one of the oldest monotheistic sects with roots in Zoroastrianism.

On Sunday, Kurdish forces retook two towns in northern Iraq from the militants while U.S. airstrikes also reportedly helped save numerous Yazidis, who had fled their homes to take refuge on Mount Sinjar in northern Iraq.

The report from AP comes at a time when Iraqi Prime Minister Nouri al-Maliki has threatened to file an official complaint against Iraqi President Fuad Massoum for not naming a new prime minister within 15 days, as required by the country's constitution, after being voted to the post on July 24.

Meanwhile, U.S. Secretary of State John Kerry urged Maliki not to foment trouble and asked the Iraqi people to stay calm despite the political upheaval in the region.

"We believe that the government formation process is critical in terms of sustaining the stability and calm in Iraq," Kerry said Monday, according to AP, adding: "And our hope is that Mr. Maliki will not stir those waters."