By Steve Holland and Justyna Pawlak
VILNIUS (Reuters) -U.S. President Joe Biden's administration will move ahead with the transfer of F-16 fighter jets to Turkey in consultation with Congress, national security adviser Jake Sullivan said on Tuesday, a day after Ankara gave the green light for Sweden to join NATO.
Turkey, which had been the main stumbling bloc on Sweden's path towards the alliance, had requested in October 2021 to buy $20 billion of Lockheed Martin Corp F-16 fighters and nearly 80 modernisation kits for its existing warplanes.
Speaking ahead of a summit of NATO leaders in Lithuania, Sullivan said Biden "had been clear that he supports the transfer."
"He has placed no caveats on this ... He intends to move forward with that transfer," Sullivan told reporters, without giving details on the timing.
U.S. Senate Foreign Relations Committee Chairman Bob Menendez, a Democrat who has blocked the F-16 sale, said on Monday he was in talks with the Biden administration about his hold and that he could make a decision "in the next week."
State Department spokesperson Matthew Miller said Secretary of State Antony Blinken had spoken to Turkish Foreign Minister Hakan Fidan and members of Congress, including Menendez, in recent weeks. "And as the national security adviser said today, we will move forward with that sale, which we do understand needs to be approved by key members of Congress," he told a daily news briefing.
Blinken pressed Fidan on Sweden's accession to NATO during calls on Wednesday and Saturday, according to State Department readouts. He spoke to Fidan again on Monday, hours before Turkish President Tayyip Erdogan announced that he had agreed to approve Sweden's accession.
"I am not going to characterize those conversations other than to say we have always made clear that we have supported the sale of F-16s to Turkey and we will continue to do so," Miller said.
Tensions between Turkey and fellow NATO member Greece - which wants to buy F-35 jets from the United States - could be a stumbling block for the F-16 sale, however. Blinken also spoke to Greek Prime Minister Kyriakos Mitsotakis on Friday.
Menendez had said he had concerns about Turkey that extended beyond Sweden joining NATO, including human rights and Turkish overflights of Greek airspace.
'THE SWEDISH BLACKMAIL'
Some diplomats and analysts believe Erdogan had been using Swedish membership of NATO to pressure Washington on the warplanes, and that Biden made a deal.
"There seems to have been a big push by the Biden administration to allow Turkey to modernise its air force and acquire new F-16s," said Camille Grand, a defence specialist at the European Council on Foreign Relations think tank.
"This push together with the Swedish efforts on the PKK front might have played an important role in convincing Erdogan to move forward on Sweden."
A former French ambassador to Washington, Gerard Araud, wrote on Twitter that "'The Swedish blackmail' paid."
Ankara had accused Sweden of doing too little against people Turkey sees as terrorists, mainly members of the outlawed Kurdistan Workers Party (PKK), which is considered a terrorist organisation by Turkey, the EU and the United States.
A statement issued by Turkey and Sweden on Monday said Sweden had reiterated that it would not provide support to the Kurdish groups and would actively support efforts to reinvigorate Turkey's EU accession process.
Russian officials said Sweden's expected accession to NATO would have "negative implications" for Russia's security and Moscow would have to respond.
The timing of both the F-16 transfer and Sweden's NATO entry remains unclear.
Turkey's parliament is not scheduled to convene until after the summer, and Hungary also still needs to ratify the accession treaty, although Foreign Minister Peter Szijjarto said in a statement on Tuesday that it was "only a technical issue".
All NATO states must ratify a new member.
NATO Secretary-General Jens Stoltenberg said Erdogan had agreed to push ratification in parliament "as soon as possible", but could not give a specific time frame.
It took two weeks for Turkey's parliament to ratify Finland's membership. Finland had applied alongside Sweden after Russia's invasion of Ukraine in February 2022 overturned the two Nordic nations' security considerations.
(Reporting by Steve Holland, Justyna Pawlak, Simon Lewis, Richard Cowan and Patricia Zengerle; editing by John Irish, Heather Timmons, Devika Syamnath and Rosalba O'Brien)
