Turkey “expects” the Trump administration to grant it waivers from U.S. sanctions related to its purchases of Iranian oil and Russian air defenses, a top aide to Turkish President Recep Tayyip Erdogan said Tuesday.

Presidential spokesman and senior adviser Ibrahim Kalin told a news conference he couldn’t be certain that the waivers would be granted. But, he said Turkey had made a strong case that should be heeded.

Turkey is seeking an extension to a waiver that allows it to import Iranian oil without U.S. penalties that were re-imposed in November after President Donald Trump pulled the U.S. out of the landmark 2015 Iran nuclear deal. The waiver expires early next month.

“We are expecting an extension for Turkey,” Kalin said. “We have made it clear we would like to continue to buy Iranian oil. People should not expect Turkey to turn its back on Iran just like that.”

The administration granted waivers to seven countries, including Turkey, and Taiwan, allowing them to continue to buy Iranian crude provided they pledged to move to cut their imports to zero. Those waivers expire on May 2.

U.S. officials have said that three of the eight waivers won’t require extensions because they have eliminated Iranian oil imports. But they have refused to say whether any of the other five will be extended. The lack of clarity has angered Iran hawks in Congress and elsewhere who say that any waiver extensions will hurt the administration’s “maximum pressure” campaign on Iran to press it to end what the U.S. terms its “malign activities” in the Middle East and beyond.

Kalin also said Turkey wants a waiver for sanctions that will likely be triggered should it take delivery of Russia’s advanced S-400 missile defense system over Washington’s objections.

Turkey’s purchase of the S-400 has created a deep rift between the NATO allies, with U.S. officials warning of significant consequences if it is finalized and Turkish officials saying it’s a done deal that won’t be cancelled.

Kalin said Erdogan and other Turkish officials have been pressing Trump to use a presidential exemption to spare Turkey from sanctions under legislation known as the Countering America’s Adversaries Through Sanctions Act, which is aimed in part at Russia’s defense industry. The exemption allows Trump to bypass the mandated sanctions should he determine it is in U.S. national security interests to do so.

“If it comes to it, of course we would expect President Trump to use his waiver,” Kalin said. He stressed that he could not speak for Trump or other U.S. officials but said that Trump had promised Erodgan that he would personally look into the situation. Kalin said he expected delivery of the S-400 system to be completed within 2 to 3 months.

In addition to the sanctions, the Pentagon and State Department have said the S-400 purchase will jeopardize Turkey’s participation in the U.S. F-35 fighter aircraft program. U.S. officials say Turkey’s use of the Russian surface-to-air missile defense system would be a threat to the F-35 program and have already suspended some aspects of Turkey’s participation.

Kalin said Turkey was hopeful the U.S. would agree to a Turkish proposal to set up a technical committee to review possible security threats posed by the S-400.

Kalin spoke to reporters at the Turkish Embassy as he wrapped up a trip to Washington with other senior officials in Erdogan’s government, including the ministers of defense, finance and trade. In addition to their meetings with U.S. officials including Treasury Secretary Steven Mnuchin and Trump’s senior adviser and son-in-law Jared Kushner, the officials all spoke at the American-Turkish Council’s annual conference on U.S.-Turkey relations. The conference was held at the Trump International Hotel.

© The Associated Press. All rights reserved.