MOSCOW (Reuters) - The Kremlin said on Monday that talks with Saudi Arabia over Moscow supplying Riyadh with advanced S-400 air defense missile systems had gone well so far despite talk of a possible U.S.-Saudi arms deal.

A frame grab taken from footage released by Russia's Defence Ministry November 26, 2015, shows a Russian S-400 defense missile system deployed at Hmeymim airbase in Syria. Russia sent an advanced missile system to Syria on November 25 to protect its jets operating there and pledged its air force would keep flying missions near Turkish air space, sounding a defiant note after Turkey shot down a Russian fighter jet. Footage released November 26. REUTERS/Ministry of Defence of the Russian Federation/Handout via Reuters ATTENTION EDITORS - THIS IMAGE WAS PROVIDED BY A THIRD PARTY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THE AUTHENTICITY, CONTENT, LOCATION OR DATE OF THIS IMAGE. IT IS DISTRIBUTED EXACTLY AS RECEIVED BY REUTERS, AS A SERVICE TO CLIENTS. FOR EDITORIAL USE ONLY. NOT FOR SALE FOR MARKETING OR ADVERTISING CAMPAIGNS. NO RESALES. NO ARCHIVE. THIS IMAGE HAS BEEN SUPPLIED BY A THIRD PARTY. IT IS DISTRIBUTED, EXACTLY AS RECEIVED BY REUTERS, AS A SERVICE TO CLIENTS - GF20000076326

Russian President Vladimir Putin hosted Saudi Arabia’s King Salman for talks at the Kremlin last week during which Saudi Arabia said it had signed a memorandum of understanding on the purchase of the S-400s.

A day later, the Pentagon said the U.S. State Department had approved the possible sale of a THAAD anti-missile defense system to Saudi Arabia at an estimated cost of $15 billion.

When asked whether a possible U.S. deal with Riyadh might affect the Russian arrangement, Kremlin spokesman Dmitry Peskov, on a conference call with reporters, said talks had been progressing well.

“We can speak only for ourselves,” said Peskov. “(But)contacts to implement this contract have been very positive and have had very good preliminary results.”

Maria Vorobyova, an official at a Russian government agency dealing with military and technical cooperation, was cited earlier on Monday as saying that a firm agreement had been reached with Saudi Arabia on the S-400s.

“An agreement has been reached with the kingdom of Saudi Arabia to deliver the S-400 air defense system, anti-tank Kornet-EM rocket systems, TOS-1A (multiple rocket launcher) systems, AGS-30 automated grenade launchers, and Kalashnikov AK-103 assault rifles,” the RIA news agency cited her as saying.

Russia also signed a contract last week for Saudi to produce the AK-103 rifles under license along with ammunition. Saudi Arabia is a longstanding U.S. ally in the Middle East and its arms deals with Moscow have caused disquiet in Washington.

When asked about fears that Saudi Arabia could use the S-400 system against Iran, a Russian ally, Peskov said Moscow’s decision to offer the missiles to Riyadh was not aimed at any third party.

“Military technical cooperation between Moscow and Riyadh is absolutely self-contained and does not target third countries in this region or other regions of the world,” said Peskov.

“Therefore we are confident that this cooperation should not be a worry for anyone.”