Turkish President Recep Tayyip Erdogan hailed the controversial delivery of the S-400 Russian missile defense system despite the threat of US sanctions as Turkey marked the third anniversary of a bloody coup attempt on Monday.

Just days before the anniversary, the first batch of the Russian S-400 defence system was delivered to Turkey despite repeated US calls to cancel the deal or face punishment.

“We have begun to receive our S-400s, some said, ‘they cannot buy them’……God willing the final part of delivery will be in April 2020,” said President Erdogan while having a discussion with a crowd who had gathered in Ankara on Monday to mark the third anniversary of a coup attempt.

The anniversary comes at a difficult moment for Erdogan. He faces a weakened economy, worsening relations with NATO ally the United States over the S-400 purchase, and a humiliating loss for his party in the recent Istanbul local election.

Erdogan said Turkey’s “next target was joint production with Russian ” for the next missile defense system.

“We are taking every measure to make sure our people do not suffer the betrayal of 15 July again or something similar,” he added.

The S-400 is known as Russia’s most advanced long-range surface-to-air missile defence system.

The S-400 missile defence system deal could result in US sanctions under the Countering America’s Adversaries Through Sanctions Act (CAATSA) instituted by the US Congress on arms purchases from Russia.

President Erdogan had earlier said that there have been no delays in the delivery of Russian S-400 air defence missiles to Turkey.

He made the remarks at a meeting with Russian President Vladimir Putin on the sidelines of the G20 Summit in Osaka, Japan.

The supplies of the S-400 missiles to Turkey will begin in the first half of July, Erdogan said earlier this month after returning from the summit of the Conference on Interaction and Confidence Building Measures in Asia held in Tajikistan’s Dushanbe.

Late on Monday, Erdogan travelled to Istanbul to inaugurate a museum dedicated to the failed coup, where he insisted on the importance of commemorating the putsch attempt to prevent “greater evils”.