"Iraq faces an existential threat and Iraq's leaders have to meet that threat," Kerry told reporters after he met with Iraqi Prime Minister Nuri al-Maliki and other high-ranking officials in Baghdad, Xinhua reported.
Kerry confirmed that the US support to Iraqi security forces "will be intense, 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 Islamic State in Iraq and Levant (ISIL) more effectively."
The US top diplomat arrived in Baghdad earlier in the day for talks with top Iraqi officials and political leaders over the current security crisis as the country is trying to curb a Sunni blitzkrieg. He is also scheduled to travel to Arbil, capital of the semi-autonomous region of Kurdistan, to meet with the Kurdish leader Masoud Barzani.
Obama govt has agreed to limited military support to Iraq
Kerry's visit is part of a tour in the Middle East to consult with US partners and allies on measures to support security, stability, and the formation of an inclusive government in Iraq, as well as other developments in the region.
His visit to the country came amid a worsening security conditions that began less than two weeks ago when armed Sunni insurgents, spearheaded by an Al Qaeda splinter group ISIL, launched a surprise offensive that led to the debacle of Iraqi security forces, and the fallen of a large part of the country's northern and western territories.
The Iraqi Shiite-led government has urged the US to raid the militants with air strikes, while the Obama administration so far only agreed on a plan of limited military support.
Later on, Kerry will travel to Brussels to participate in a NATO foreign ministers' meeting.