President Obama will meet with Turkish President Recep Tayyip Erdogan on the sidelines of the G-20 summit in China next week to try to resolve a clash unfolding in northern Syria, where one faction of forces backed by the U.S. and Turkey is clashing with another group of Syrian Kurds the CIA has supported, according to the White House.

The meeting takes place nearly one week after Vice President Joe Biden traveled to Turkey and held meetings with Turkish officials, including one with Erdogan, to try to reassure the ally of U.S. support.

The diplomatic effectiveness of Biden's trip received mixed reviews as Turkey released photos of a stone-faced Erdogan sitting with Biden.

Turkish forces were able to clear an area south of the city of Jarabulus of Islamic State fighters, but are now reportedly conducting airstrikes against Syrian Kurds that the U.S. backs.

White House deputy national security adviser Ben Rhodes said Monday that Turkey has the support of the U.S. for clearing Jarabulus of the Islamic State and to secure its border, but he said, "we do not support and we would oppose efforts to move south and engage in activities against" Syrian Kurds "[who] we have supported."

"Further action against [Syrian Kurds] would complicated efforts to have the united front against ISIL we want," Rhodes said, referring to the Islamic State by a common acronym.

The Pentagon said Monday morning that the U.S. is calling on its allies to "stand down immediately and take appropriate measures to deconflict."

"While we are closely monitoring reports of clashes south of Jarabulus — where ISIL is no longer located — between the Turkish armed forces, some opposition groups and units that are affiliated with the [Syrian Defense Force], we want to make clear that we find these clashes unacceptable," Pentagon spokesman Peter Cook told the Washington Examiner in an email.