Turkish Foreign Minister Hakan Fidan called on US counterpart Antony Blinken on Sunday to use Washington’s clout with Israel to stop Israeli attacks on Gaza and the West Bank, according to a Turkish diplomatic source.

Turkey has sharply criticized Israel, demanding a complete ceasefire and the prosecution of Israeli leaders in international courts for war crimes. Turkey also criticizes Western support for Israel. Turkey favors a two-state solution to the decades-old conflict.

Washington, Israel’s closest ally, has repeatedly said it supports Israel’s right to defend itself after the cross-border rampage by Hamas militants on Oct. 7, but has stepped up calls on Israel to act with restraint in its campaign, which has killed nearly 19,000 people, according to Gaza health officials, and laid much of the Gaza Strip to waste.

Fidan told Blinken that the situation in Gaza and the West Bank was worsening due to the Israeli attacks, the source said. Turkish President Tayyip Erdogan told U.S. President Joe Biden on Thursday that the United States had a historic responsibility to achieve a ceasefire in Gaza.

“Fidan emphasised the need for Israel to be made to sit at the (negotiating) table after a full ceasefire is achieved, in order to start a process aimed at realising a fair and lasting peace based on a two-state solution,” the source added.

While Turkey has slammed Israel as a “terror state” for its attacks on Gaza, it has maintained its commercial ties, drawing criticism from opposition parties and some regional powers.

Trade Minister Omer Bolat said on Friday that Turkey’s trade with Israel had dropped 48% since Oct. 7, and that most of the trade was being carried out by international firms operating in Turkey. He added that goods being sent to Palestinians also had to go through Israel.

The source said Fidan and Blinken also discussed bilateral ties, Sweden’s NATO membership bid, which the Turkish parliament is yet to ratify, and Ankara’s request to purchase F-16 fighter jets from the United States.

“During the call, in which the importance of acting in line with the spirit of alliance was emphasised, Sweden’s NATO bid, the F-16 issue and cooperation on defence industry were among issues over which views were exchanged,” the source said, adding the call was held at Blinken’s request.

Turkey asked in October 2021 to buy 40 Lockheed Martin Corp (LMT.N) F-16 fighters and 79 modernization kits for its existing warplanes. The Biden administration backs the $20 billion sale, but there have been objections in the U.S. Congress over NATO member Turkey’s human rights record and over its delaying the Swedish bid.

After long-time non-alignment, Sweden applied to join NATO to bolster its security in response to Russia’s full-scale invasion of Ukraine in February 2022, but has been left waiting due to resistance from alliance states Turkey and Hungary.