A spokesman for the United Nations’ Secretary-General says the Israeli leader’s vow to annex the Jordan Valley would be a “serious violation of international law.”

The particularly strong rebuke from the world body follows a chorus of criticism against Israeli Prime Minister Benjamin Netanyahu for his promise to annex the area if he wins re-election next week.

In a statement, spokesman Stephane Dujarric also said the pledge would be “devastating” to the potential for peace with the Palestinians.

Russia’s Foreign Ministry also reportedly blasted the step ahead of a meeting between Netanyahu and Russian President Vladimir Putin on Thursday.

Netanyahu said on Thursday that continued rocket fire from Gaza is making another war against militants in the coastal strip inevitable, his latest headline-grabbing announcement just days before he seeks re-election in a nationwide vote.

Netanyahu said advanced plans were in place to strike Gaza and that he would decide the optimal timing of the offensive, given the Gaza Hamas rulers’ unwillingness to stop the daily barrages.

The Israeli military has responded to the attacks with limited strikes against Hamas installations that have caused no casualties and little damage, and has refrained from risking a larger conflagration on the eve of Israelis heading to the polls.

The Israeli leader has been criticised for failing to respond harshly to the rockets, which have been frequently sending residents of southern Israel scurrying for cover.

Netanyahu, who counts on the working-class, Gaza border towns as part of his electoral base, was himself whisked away by bodyguards from a campaign event on Tuesday when Palestinians fired rockets toward the area where he was.

Israel withdrew from the Gaza Strip in 2005 and Hamas fighters overtook the territory by force two years later. Israel and Hamas have fought three wars and engaged in several other rounds of violence over the past decade.

“I do not wage war unless it is a last resort and I don’t risk the lives of our soldiers and citizens just to get applause,” Netanyahu said in an interview with Kan Reshet Bet Radio.

“We will probably have no choice but to set out on a big campaign, a war against the terror forces in Gaza.” “I won’t start it one minute before we are ready, and we are preparing for a ‘different war’,” he added, shortly before flying to Russia for a meeting with President Vladimir Putin.

It was Netanyahu’s first major interview to a mainstream media outlet in a frenetic campaign in which he has been dictating the agenda with a dizzying array of maneuvers.

Just this week, he alleged fraud in Arab voting areas and pushed for legislation to place cameras in polling stations on election day. He also claimed to have located a previously unknown Iranian nuclear weapons facility and vowed to annex the heart of the West Bank if he wins re-election.

His pledge to extend Israeli sovereignty over the Jordan Valley sparked international condemnation. Stephane Dujarric, spokesman for the UN-general, said that if it were carried through it would be a “serious violation of international law.”

Netanyahu said it was important to act now as President Donald Trump prepares to unveil his Mideast peace plan after the elections next Tuesday in Israel. The move was widely viewed in Israel as Netanyahu’s latest stunt to draw in right-wing voters in a hard-fought campaign.

In a statement issued on Wednesday evening, the Russian foreign ministry said it took note of Netanyahu’s announcement and the “highly negative reaction in the Arab world.”

It said it would share its concerns with Israel since “implementation could trigger a sharp escalation in the region and undermine hopes for establishing a lasting peace between Israel and its Arab neighbours.”

Prior to his departure to Sochi, Netanyahu said the focus of his talks with Putin would be to promote the “joint goal” of removing Iranian forces from neighboring Syria.

Netanyahu and Putin have met regularly in recent years to coordinate military activities in Syria.

Netanyahu has for years argued for aggressively countering Iran’s nuclear programme and its regional belligerency and often takes in pride in having a strong working relationship with both Putin and Trump.

Agencies