Washington's top diplomat, John Kerry, flew in to Baghdad on Monday for a face-to-face meeting with Iraqi Prime Minister Nouri al-Malaki. Their discussion lasted over an hour and a half.

According to a statement from the prime minister's office, Maliki told Kerry that the recent onslaught led by jihadists from the Islamic State in Iraq and the Levant (ISIS) "represents a threat not only to Iraq but to regional and international peace."

Maliki's Shiite-dominated government has been accused of fueling the crisis by excluding Sunni Muslims from power and pursuing a sectarian agenda. It's something Kerry was expected to bring up in the closed-door talks. He told journalists afterward that Iraq's leaders faced a "moment of decision."

"Iraq faces an existential threat and Iraq's leaders have to meet that threat," Kerry said on Monday.

After meeting Maliki, Kerry was also scheduled to speak with influential Shiite clerics and Parliament Speaker Osama al-Nujaifi, one of Iraq's highest-ranking Sunnis, along with Foreign Minister Hoshyar Zebari, a Kurd.

Iraq's parliament is working to set up a new government following elections in April.

Border controls lost

While Kerry was in Baghdad, the ISIS militants and those aligned to them tightened their grip on the north and west of Iraq.

Neighboring Jordan has boosted security along its frontier after Sunni tribes took the Turaibil desert border crossing between the two countries from Iraqi government forces.

The tribal leaders were reportedly in negotiations to hand the crossing over to ISIS, which already controls several main entry points to Syria. With ethnic Kurdish forces in control of a third border area with Syria to the north, it leaves an 800-kilometer (500 miles) stretch of Iraq's western frontier outside the control of government troops.

On Monday dozens of people were also killed in an attack by gunmen on a police convoy transporting prisoners south of Baghdad.

se/mkg (AP, AFP, dpa, Reuters)