ANKARA (Reuters) – A Turkish military plane carrying medical supplies and protective equipment was heading for the United States on Tuesday to deliver aid to its NATO ally battling the coronavirus outbreak.

The United States, which has the highest death toll and reported cases in the global pandemic, welcomed the “generous donation” of 500,000 surgical masks, 4,000 overalls, as well as disinfectant, goggles and face shields.

“We are proud to announce that Turkey will deliver medical supplies to the United States, upon our NATO ally’s request, to support America’s fight against the coronavirus,” Turkey’s Communications Directorate said.

The aid comes at a potentially pivotal time in U.S.-Turkish relations, which have been strained by disputes over Iran sanctions, Syria policy and Turkey’s acquisition of Russian missile defence systems.

Turkey had planned to deploy the S-400 missile defences this month, but a senior Turkish official said that Ankara will delay the move – which would likely trigger U.S. sanctions – while it tackles the coronavirus and tries to support the economy.

Ankara has also asked the U.S. Federal Reserve for currency swap facilities to help stem the economic impact of the disease.

“As this delivery indicates, the U.S.-Turkey relationship is strong and one of our most important alliances,” U.S. Ambassador to Turkey David Satterfield said.

Ankara has already sent medical shipments to 55 countries, including Italy, Spain, Britain, Iran, China and others in the Balkans or Africa. Last month it flew 500,000 coronavirus testing kits to the United States.

Turkey also has one of the world’s highest number of registered cases of COVID-19, but officials have reported a slowdown in new cases and fatalities.

Turkey has 112,000 confirmed cases, of which 2,900 have died, according to the Health Ministry. The daily death toll dropped to 95 on Monday, an eighth consecutive daily fall, while new cases fell for a third day running to 2,131.

The United States has reported more than 957,000 cases and nearly 54,000 deaths.

(Reporting by Tuvan Gumrukcu; Editing by Dominic Evans and Nick Macfie)