An Israeli newspaper reported Friday that Israel's prime minister secretly talked peace with Syria through an American mediator, offering far-reaching land concessions, but negotiations ended because of the Syrian civil war.

The prime minister's office said the initiative came from the U.S. and denied Israel had accepted it, implying the matter was leaked to improve President Barack Obama's image in the run-up to U.S. presidential elections.

The newspaper, Yediot Ahronot, reported that the talks were mediated by Obama envoy Fred Hoff from late 2010 to early 2011. The report said Prime Minister Benjamin Netanyahu offered to return the Golan Heights to Syria as its part of a peace deal. Israel captured the strategic territory from Syria in the 1967 Mideast war.

The uprising that evolved into the Syrian civil war started in March 2011, putting an end to the reported contacts.

It's not the first time such terms have reportedly been on the table.

American businessman and Netanyahu associate Ronald Lauder reportedly negotiated a similar Israel-Syria peace deal in 1998, during Netanyahu's first term as premier. At the time, Netanyahu denied that claim. Netanyahu's successor a premier, Ehud Barak, also offered a Golan withdrawal for peace in 2000, but the talks broke down over issues like exact borders and terms of peace.

According to the Friday report, Netanyahu and Barak, now Israel's defense minister, were willing to withdraw from the Golan in exchange for a full peace treaty that would include an Israeli expectation — but not a public declaration by Syrian President Bashar Assad — that Syria would sever its close ties with Iran. Syria wanted an Israeli withdrawal within two years, the report said, while Israel wanted more time to pull out.

The negotiations were conducted in deep secrecy, the report claimed. Only a small number of top Israeli officials were involved, and meetings took place outside of the prime minister's office to keep the talks classified. Netanyahu and Barak even kept the talks secret from top officials in the Shin Bet and Mossad intelligence agencies, the paper said.

The prime minister's office said in a statement Friday that Israel never accepted the American initiative and that it is no longer relevant.

"This is one initiative of many that have been offered to Israel in recent years," the statement read. "The initiative is old and irrelevant, and its current publication stems from political considerations."

Israel Radio reported Friday that Netanyahu's associates said he never considered withdrawing from the strategic Golan plateau overlooking northern Israel, and they linked the publication of the American-mediated talks with the U.S. presidential elections.

The U.S. Embassy in Israel had no comment.