ISTANBUL — Coming together over crisis has been a hallmark of the relationship between the United States and Turkey in recent years. So it was an especially troubling sign of degraded trust that a meeting between Turkish and American diplomats was canceled last week because it seemed more like an ambush than a consultation.

A corruption inquiry of Prime Minister Recep Tayyip Erdogan’s inner circle had been quickly intensifying, and late in the week, the Turkish foreign minister requested through an intermediary a meeting with the American ambassador, Francis J. Ricciardone Jr., to discuss the crisis, according to interviews with American and Turkish officials.

For days, American diplomats had been privately pleading that the Turks resist trying to divert attention by playing off the investigation as part of a foreign plot. But on Saturday, before the scheduled meeting, the machinery was obviously spinning.

Pro-government newspapers featured Mr. Ricciardone on their front pages, and later in the day the Turkish news media reported that the foreign minister, Ahmet Davutoglu, was set to call Secretary of State John Kerry and banish the American ambassador over an unspecified American role in the corruption inquiry. And Mr. Erdogan embarked on a series of speeches in which he, too, hinted at American treachery and suggested Mr. Ricciardone might be expelled from the country.