Prime Minister Benjamin Netanyahu’s government was caught off guard by the United Arab Emirates’ public warning that Israeli annexation of the West Bank was a “red line” that would spell an end to regional integration, The Washington Post reported Saturday, citing an Israeli official.

“The Emirates have expressed concerns about [annexation] before through other channels, but the statement came as a surprise,” the unnamed official was quoted as saying. “It’s very unusual.”

The warning was issued by Emirati special envoy Lana Nusseibeh in an interview with The Times of Israel on Tuesday and a subsequent statement. Further warnings were issued through backchannels, to the point that annexation was taken off the agenda for Netanyahu’s Thursday night cabinet meeting, The Post said, citing three people with knowledge of the matter.

The public warning was particularly stark coming from the UAE, which took the landmark step of normalizing relations with Israel in 2020 under the so-called Abraham Accords, becoming the first Arab nation to do so in over a quarter century.

The UAE decision to normalize relations with Israel came at a time when Jerusalem was also considering annexing parts of the West Bank, and dropping the matter was widely reported to have been a condition set by Abu Dhabi for the agreement.

Two of the people cited by The Post said the warning came after Netanyahu frustrated Emirati officials by appearing to disregard warnings made in private. The Emiratis were also said to have become frustrated with US officials, including Ambassador to Israel Mike Huckabee, for seeming to take Netanyahu’s lead on the issue of annexation.

According to The Post, “Emirati officials now believe the United States and Israel are taking their concerns more seriously.”

Approached for comment, a White House spokesperson referred to US Secretary of State Marco Rubio’s remarks on Thursday that West Bank annexation was “not a final thing,” the paper said.

“That’s something being discussed among some elements of Israeli politics,” Rubio told reporters in Ecuador, adding that he would not “opine on that today.”

Rubio added that Israeli talk of West Bank annexation was a “wholly predictable” response to Western nations’ pledge to recognize a Palestinian state at the UN General Assembly this month.

On Wednesday, Finance Minister Bezalel Smotrich called for annexation of some 82% of the West Bank as a way to “bury the idea of a Palestinian state” after countries including France, Britain, Canada and Australia announced plans to recognize Palestinian statehood.

Earlier this week, Hebrew media reported that Netanyahu was set to discuss annexation with senior ministers on Thursday, but the discussion was scuttled following the Emiratis’ public warnings, according to the Post.

Israel’s presence in the West Bank, which it has controlled since the Six Day War of June 1967, is considered illegitimate by most countries, with the notable exception of the United States during the two terms of US President Donald Trump.