U.S. Secretary of State John Kerry returned to Iraq on Tuesday for the second consecutive day to urge leaders of Iraq's autonomous Kurdish region to support Baghdad against a growing Sunni insurgency that threatens to destroy the country.

The top U.S. diplomat was in Erbil to have a "heart to heart with Kurdish officials" and make it clear that the Obama administration believes it is in "nobody's interest to have kind of al-Qaida on steroids" on its southern border, said a senior U.S. official, according to CBS News.

However, to prevent that from happening, U.S. officials believe the Kurds need to remain part of the Iraqi government to make sure a moderate Sunni component can clear territory seized by al-Qaida-linked splinter group Islamic State of Iraq and al-Sham, or ISIS. One U.S. official warned that if the Kurds withdraw from the Baghdad political process, "it will accelerate a lot of the negative trends" in Iraq and the wider region.

The president of the Kurdish Regional Government announced that the country was facing a "new reality" after ISIS recently seized large parts of western Iraq, including the city of Mosul.

"We are facing a new reality and a new Iraq," Barzani told Kerry shortly after Kerry arrived in Erbil on Monday morning, Reuters reports.

President Massoud Barzani's words will likely renew concerns in Washington that Erbil might seek independence or greater autonomy from Baghdad if Iraq remains unstable in upcoming months.

"As everybody knows, this is a very critical time for Iraq, and the government-formation challenge is the central challenge that we face," Kerry said during his one-hour meeting with Barzani and Kurdish leaders.

U.S. officials also acknowledged that Barzani's administration might not be willing to return Kirkuk to Baghdad's writ even if the Kurds don't declare formal independence.