The US Secretary of State, John Kerry, has been holding talks with Iraqi leaders on a surprise visit to Baghdad.

He urged Nouri al-Maliki’s Shia-led administration to give more power to the opposition.

Maliki has said he is committed to forming a new government by July 1.

Meanwhile, Iraqi Kurdish leader, Massoud Barzani, has said he would seek formal independence from the rest of Iraq as the situation in the country worsens.

The US Secretary of State John Kerry said: “the support will be intense and sustained and if Iraq’s leaders take the necessary steps to bring the country together, it will be effective. It will allow Iraqi security forces to confront ISIL more effectively and in a way that respects Iraq’s sovereignty while also respecting America’s and the region’s vital interests.”

Kerry visit comes as insurgents, led by the group ISIL, expand their offensive in Iraq.

It’s been reported that the country’s main oil refinery in the town of Baiji had earlier been captured after a ten day siege, however Iraqi troops had retaken control of it according to the government.

All border crossings to Syria and Jordan remain under the control of Sunni insurgents.