A member of the Syrian Democratic Forces, made up of U.S.-backed Kurdish and Arab fighters, takes position near the village of Bir Fawaz during their offensive against the Islamic State on Feb. 8. (Delil Souleiman/AFP/Getty Images)

Turkish President Recep Tayyip Erdogan took his proposal for a Turkish-backed assault against the Islamic State’s self-proclaimed capital of Raqqa to the Sunni Arab states of the Persian Gulf on Monday, telling an audience in Bahrain that he wants to create a “safe zone” in that part of Syria.

Speaking on the first stop of a three-nation gulf tour, Erdogan said the safe zone would encompass 3,475 square miles and include the Syrian town of Manbij, which was taken from the Islamic State in August by Syrian Kurds working closely with the U.S. military.

The Turkish offer to participate in the Raqqa battle is not new, but it has been revived amid reports that President Trump has ordered an overhaul of the Obama administration’s plan to arm the Syrian Kurds to assault Raqqa. Turkey vehemently opposes the Pentagon’s close military relationship with the Syrian Kurds, which became a major source of tension between Turkey and Washington during President Barack Obama’s last year in office. The Syrian Kurdish militia, the People’s Protection Units (YPG), has ties to Turkey’s own Kurdistan Workers’ Party (PKK), which is designated as a terrorist organization by Washington and Ankara and is waging an insurgency in Turkey to secure autonomy for Kurds.

Trump’s promise to create a “safe zone” in Syria — long rejected by the Obama administration — also appears to have encouraged Erdogan to resurrect an idea that had lapsed since the defeat of the Syrian rebels in Aleppo late last year. Originally promoted by the Syrian opposition, with Turkish support, the concept envisaged enforcing a no-fly zone to prevent the Syrian government from carrying out airstrikes against civilians.

How this latest proposal would work wasn’t clear, but Erdogan said the zone would be used to give sanctuary to Arab and Turkmen Syrians and would be “terrorist-free” — an apparent reference to the YPG Kurds as well as the Islamic State.

Erdogan said Turkey envisions participating in the Raqqa offensive as part of the U.S.-led coalition, but he also has made it clear on a number of occasions that he expects Trump to sever Washington’s connections to the YPG.

There has been no indication from Washington that the United States intends to abandon its alliance with the Kurds, who have emerged as the Pentagon’s most effective military partner in Syria. The Kurds have been making steady progress with a three-month-old offensive to isolate and encircle Raqqa and are within a few miles of the city.

Meanwhile, Turkish troops and their Arab Syrian rebel allies have been bogged down for the past two months in a fierce battle to capture the Islamic State-held town of Al-Bab, more than 100 miles away. Turkey intervened in Syria in August to help Syrian rebels push the Islamic State out of areas bordering Turkey and also to drive a wedge between two expanding areas of Kurdish control.