WASHINGTON, Nov 17 (Reuters) - Israel is in talks with the United States to acquire an additional 20 Lockheed Martin Corp F-35 fighter jets, a senior Israeli defense official said on Wednesday.

Lieutenant General Gabi Ashkenazi said Israel would welcome another 20 fighter jets on the heels of a deal signed in October to buy about 20 of the radar-evading jets at a cost of about $96 million per aircraft.

As I understand -- and that's the latest information I have on this issue -- it's still under negotiation between the Israeli government and the administration, he said, speaking at a news conference alongside Admiral Mike Mullen, the top U.S. military officer.

I don't know the final decision, Ashkenazi said.

Some media had reported the Obama administration offered the additional jets to Israel in exchange for a three-month freeze on construction of new settlements, a key issue in efforts to broker Israeli-Palestinian peace.

Israel signaled on Tuesday it had delayed approving U.S. proposals for a freeze on West Bank settlement building so that peace talks can resume, saying it wanted the ideas in writing.

Israeli sources said the proposals, made verbally during a meeting between U.S. Secretary of State Hillary Clinton and Israeli Prime Minister Benjamin Netanyahu in New York last week, included an F-35 offer worth $3 billion and pledges of enhanced U.S. diplomatic support at the United Nations.

Israel has said the first batch of jets, to be received from 2015 through 2017, would boost the country's ability to defend itself against any Middle Eastern threat. (Reporting by Missy Ryan; Editing by Philip Barbara)