ISTANBUL — A Turkish military offensive against Syrian Kurdish fighters appeared to be averted  as the United States and Turkey announced Wednesday that they had agreed to “address Turkish security concerns” and work together on the establishment of a “safe zone” in northern Syria.

 But statements released by the two governments, using virtually identical language, contained little detail about what exactly had been agreed upon. Critically, the statements, released by the U.S. Embassy in Ankara and Turkey’s Defense Ministry, did not say whether the thorniest issue — the size and complexion of the safe zone — had been resolved.

The Trump administration had worked furiously in recent weeks to head off a Turkish offensive against a U.S.-backed force in Syria that had led the ground offensive against the Islamic State militant group.

The force controls large swaths of territory along the Syrian-Turkish border and is dominated by Syrian Kurdish fighters, whom Turkey considers a threat to its security.

The threat of Turkish military action came after months of haggling over the establishment of a safe zone that would push the Syrian Kurdish fighters back from the border. Over U.S. objections, Turkey had argued for a larger safe zone and for sole Turkish control over the area.

U.S. officials feared a Turkish invasion could happen as soon as Thursday. The agreement announced Wednesday said that the U.S. and Turkish delegations had agreed to a “rapid implementation of initial measures to address Turkey’s security concerns.”

A joint operations center in Turkey would “coordinate and manage the establishment of the safe zone together.”

A U.S. official said that “considerable agreement” had been reached but that there are “still issues to work out.”

“This gives us room to take initial joint Turkish-U.S. actions,” said the official, who spoke on the condition of anonymity because of the sensitivity of the issue. It was unclear whether progress had been made on considerable differences between the two governments on the size and patrolling of a safe zone.

That statement also said that the safe zone “shall become a peace corridor, and every effort shall be made so that displaced Syrians can return to their country” — language that appeared aimed at addressing rising anxiety in Turkey about the growing population of Syrian refugees.

President Recep Tayyip Erdogan’s government has responded to that domestic anger by promising that the refugees will soon be able to return to Syria, including to areas secured by the Turkish military. Advocates for the refugees say that difficult conditions in Turkish-controlled areas and across Syria make it unlikely that many refugees living in Turkey will soon return.

The agreement announced Wednesday appeared to have lowered the temperature, at least for the moment, of just one of the many disputes roiling the U.S.-Turkish relationship. The Trump administration has also objected to Turkey’s purchase of a sophisticated Russian air defense system and responded by canceling Ankara’s participation in the production and purchase of the F-35 next-generation American stealth aircraft.