With hostility between the United States and Iran roiling the region, for instance, he warned that the Trump administration’s hard-line toward Iran was a problem for Turkey and other countries that rely on Iranian oil. “How can I ensure heating for my citizens in wintertime?” he said.

Tensions between the United States and Turkey have also risen after Turkey’s purchase of the S-400 missile system, Russia’s most advanced antiaircraft weaponry. The purchase would set off mandatory United States sanctions against Turkey, and it could create another slide in the value of the Turkish lira.

Mr. Erdogan said that the missile system would arrive in Turkey in the first half of July, that 100 technicians had already been trained, and that the sites for the weapon’s deployment had been selected. Yet he seemed confident that his apparent rapport with Mr. Trump should be enough to ease the disagreement — and possibly avoid sanctions.

“They should think deeply, because losing a country like Turkey will not be easy,” Mr. Erdogan said of the United States. “If we are friends, if we are strategic partners, then we should handle this issue between each other.”

“I don’t think at all that the sanctions will happen,” he added.

Mr. Erdogan acquired sweeping new powers last summer when the country switched to a presidential system, and in recent years he has shown no hesitation to rule in an authoritarian style. He remains Turkey’s most popular politician by far, but recent polling in Istanbul has been one of several signs that the electorate is growing weary of the dominance of Mr. Erdogan and his party.