Chief Israeli negotiator and Justice Minister Tzipi Livni struck a solemn tone on Facebook Wednesday night, calling the reconciliation agreement signed between Hamas and Fatah “a bad step.”

The agreement, by which the rival Palestinian factions agreed on Wednesday to form a unity government within five weeks and hold new elections within six months after that, was immediately panned by both Israel and the US. The Prime Minister’s Office canceled a scheduled evening meeting between Livni, chief Palestinian negotiator Saeb Erekat and US mediator Martin Indyk.

“At this very hour, I was supposed to be at a meeting with the Palestinians aimed at continuing the negotiations, after there was progress in talks yesterday,” Livni posted on Facebook.

“The reconciliation agreement that Mahmoud Abbas signed with Hamas is a bad step, which not only caused the cancelation of the meeting, but cast a heavy shadow on the possibility to progress.

“We have a duty, even when we want peace, not to stop seeing reality with eyes wide open: Hamas combines religious Muslim extremist ideology with terrorism and doesn’t recognize our right to exist.”

Prime Minister Benjamin Netanyahu called US Secretary of State John Kerry to complain about the agreement, according to a senior government official.

Netanyahu told Kerry that Fatah’s reconciliation with Hamas was a “Palestinian modus vivendi,” the official said. “Whenever it comes to decision time, the Palestinians run away,” the prime minister reportedly told Kerry. “Whoever wants peace with Hamas is not interested in peace with Israel.”

The official did not say how Kerry responded to Netanyahu’s words.

“The international demand based on the three conditions set by the Quartet must be adhered to,” Livni added in her post. “Recognition of Israel, an end to violence and recognition of all previously signed agreements between Israel and the Palestinians. This has been my clear and consistent stance.

“In front of us lies a complicated new challenge, which I’m afraid serves the extremists.”