KIEV, Dec. 27 – U.S. Vice-President Joe Biden may have personally asked President Petro Poroshenko for Ukraine to vote in favor of an anti-Israeli resolution by the U.N. Security Council, Tablet Magazine reported Tuesday, citing sources.

Ukrainian-Israeli relations were strained by the approval of the resolution that urges Israel to “immediately and completely cease all settlement activities in the occupied Palestinian territory.”

Israel accused the U.S. of campaigning behind the scene for the U.N. Security Council to approve the resolution. The U.S. abstained during the vote, refusing to exercise its power of veto.

“One tangible consequence of the high-level U.S. campaign was a phone call from Biden to Poroshenko, which succeeded in changing Ukraine’s vote from an expected abstention to a ‘yes,'” Tablet reported.

“According to one U.S. national security source, the Obama Administration needed a 14-0 vote to justify what the source called ‘the optics’ of its own abstention,” Tablet reported.

“Did Biden put pressure on the Ukrainians? Categorically yes,” said a highly-placed figure within the Israeli government with strong connections to Ukrainian government sources, who confirmed to Tablet that the U.S. had put direct pressure on both the Ukrainian delegation—and on Poroshenko personally in Kiev. “That Biden told them to do it is 1000% true,” the source said.

The phone call between Poroshenko and Biden, which took place on December 19, has been officially acknowledged by both parties. The Ukrainian presidential administration’s official statement on the particulars of the discussion contains no mention that the settlement vote was discussed.

A spokesman for the Ukrainian Presidential administration refused to either confirm or deny that a section of Biden’s call not covered in the read-out consisted of the US Vice President lobbying Ukraine to vote “Yes.”

Israeli Prime Minister Benjamin Netanyahu on Sunday accused the Obama Administration of working secretly to have the resolution approved. “We have no doubt that the Obama administration initiated it, stood behind it, coordinated its versions and insisted upon its passage,” Netanyahu said.

The resolution, which declared Jewish settlement anywhere in the West Bank including the Old City of Jerusalem to be in violation of international law, passed by 14-0, with Ukraine voting ‘yes.’ Many in Israel see the vote as a game-changing action after the U.S. for decades has provided diplomatic guarantees to Israel the resolution would never be approved.

Ukraine on Monday called in Israeli ambassador to Kiev for clarification after Israel’s decision to cancel a scheduled visit by Prime Minister Volodymyr Groysman over the vote.

The Foreign Ministry expressed its “disappointment” to Eliav Belotserkovsky at the “emotional reaction of some Israeli officials and politicians” following the passage of the resolution, according to the ministry.

Although Ukraine sees Israel as an ally, the Ukrainian vote over the resolution was constrained by concerns over accusations of hypocrisy and double standards over the issue of Russian’s illegal occupation and annexation of the Crimean peninsula, according to officials at the Ukrainian Foreign Ministry.

Ukraine is reliant on the application of the same exact statutes of international law on the issues of settlement and occupation in its own international crusade to have Russia withdraw from the territories that it has occupied, the officials said.

It would be counterproductive for Ukraine to take positions that would leave it open to diplomatic mockery—or worse—from the Russian side, the officials said. (tm/nr/ez)