As radical Sunni militants snatch city after city in their march to Baghdad, U.S. Secretary of State John Kerry arrived in Iraq on Monday during the country's tensest time since the U.S. withdrawal of troops.

He'll meet with Prime Minister Nuri al-Maliki, the man some say needs to step down.

With al-Maliki's Shiite-led government losing more ground to militants from the Islamic State in Iraq and Syria (ISIS), Kerry has implored the leader to rise above "sectarian motivations" to become more inclusive and more representative of its population.

Kerry will also meet with Iraq's foreign minister as well as both Shiite and Sunni leaders.

His trip will "emphasize our highest-level commitment to Iraq during this time of crisis," a State Department official said.

Kerry will also speak with key leaders about forming a new government "in line with the constitutional timeline that they're on."

But outside the rooms of high-level talks, parts of Iraq are falling by the day.

See the latest on the crisis that is spilling far beyond Iraq's borders from CNN.com.