"We haven't seen a diminishing effect on our security relations. Turkey continues to be a strong NATO ally," Obama said, Reuters reported.
"They are working with us to defeat ISIL and are an important partner on a whole range of security issues in the region," he said, using an acronym for Daesh.
Turkey says the United States and other Western allies have not been sufficiently supportive of its efforts to root out those responsible for the failed putsch.
Since the coup attempt, in which rogue soldiers tried to topple Turkish President Tayyip Erdogan's government, Turkey has removed 80,000 people from public duty and arrested many of them, accusing them of sympathizing with the plotters.
Critics say Erdogan has used the coup attempt as a pretext to curtail dissent.
Obama said the United States would give "honest feedback" to Turkey if it believes the steps Ankara is taking after the coup jeopardize relations with Washington.
Turkey says the mastermind behind the attempted overthrow was US -based Turkish businessman, Fethullah Gulen, and it has demanded his extradition.
Turkish officials say Erdogan will bring up the issue with Obama when the two leaders meet on Sunday on the sidelines of the G20 summit in China.