Having already delivered one division of the S-300 missile system to Iran this year, Russia plans to provide several more of them to Tehran before the end of 2016, Vladimir Kozhin, an aide to President Vladimir Putin, said Thursday. Kozhin’s comments, reported by Interfax agency, came days after another federal official in Moscow said the country would do its best to meet its commitment to Iran.

The two countries had signed a deal in 2007, for Iran to buy several divisions of the S-300 missile system from Russia. However, after the U.N. Security Council imposed sanctions on Tehran for its nuclear pursuits, Moscow did not deliver the missiles. After the sanctions were lifted in January this year, Tehran demanded Moscow to fulfill its part of the deal.

Initially, Russia did not comply and Iran filed a lawsuit in response. According to Interfax, with the deliveries having started, Iran’s lawsuit is in the process of being withdrawn, even though a time for processing the withdrawal wasn’t clear.

“We have a signed contract with Iran, the first batch has now been unloaded, approximately a battalion. We will continue to fulfill our commitments until year-end,” Kozhin said, according to a Sputnik report.

On Monday, Alexander Fomin, director of the Federal Service for Military-Technical Cooperation, told reporters Russia was making the best effort it could to uphold the $900 million contract for delivering five missile systems to Iran.

According to local news agency Tass, Fomin also denied reports of Russia selling tanks to Iran. He said Wednesday: “Such deals might be possible only when the bans are gone. Tanks, ships, missiles and other attack weapons fall under U.N. sanctions.” He also ruled out discussion on any new contracts for weapons with Iran.