United States President Donald Trump spoke with Turkish President Recep Tayyip Erdogan on Friday to discuss the dispute between Qatar and Gulf and Arab states.
Saudi Arabia, the United Arab Emirates (UAE), Bahrain and Egypt cut off economic and diplomatic ties with Qatar earlier this month and issued an ultimatum with 13 demands, accusing Doha of supporting extremist groups.
Qatar, however, denies the claims.
The White House, in an official release, said Trump and Erdogan spoke about ways to overcome the crisis "while ensuring that all countries work to stop terrorist funding and to combat extremist ideology."
Turkey has backed Qatar in its rift with the Arab states and is seeking to mediate the crisis.
"President Trump emphasised the importance of all our allies and partners increasing their efforts to fight terrorism and extremism in all its forms," the White House statement added.