UN Special Envoy to the Middle East Nikolay Mladenov told Palestinians never to give up on their dream of a state, saying Israeli annexation plan is a breach of international law.

Speaking during an anti-annexation rally held in the occupied West Bank city of Jericho, in the Jordan Valley, Mladenov repeated the UN position that Israeli annexation would violate international law, adding that it might “kill the very idea that peace and statehood for the Palestinians are achievable through negotiations.”

“You’re not renting a house here, this is your home. You do not throw away the keys to something that you have been building for 25 years. You protect it and you invest in the future, a future that is built on shared values of democracy, accountability and prosperity for everyone,” he said.

“People of Palestine, do not despair — do not give up, do not give up, never give up,” Mladenov said, “because peace is what we’re all here for.”

He also observed a moment of silence with the crowd over the shooting death of Iyad Halak, a young autistic Palestinian man from East Jerusalem, at the hands of Israeli police who say they mistook him for a terrorist.

“Iyad is the latest victim in a senseless number of killings and deaths of both Israelis and Palestinians. His death reminds us how expensive and how precious peace is and how difficult it is to keep,” Mladenov said.

Halak’s mother also spoke at the protest, condemning what she called “despotic” Israeli rule in Jerusalem and saying that she hoped her son would be “the last martyr.”

Monday’s mass rally against Israel’s planned annexation of parts of the West Bank drew thousands to the Jordan Valley, despite Israeli forces turning away buses carrying protesters to the event.

It was the largest rally of its kind since Trump in January unveiled his controversial plan for Israeli-Palestinian peace, which gives Israel a green light to annex illegal West Bank settlements and the strategic Jordan Valley, amounting to some 30 percent of the territory.

In addition to the UN’s Mladenov, European Union representative Sven Kühn von Burgsdorff, as well as the ambassadors of Russia, China, Japan, and Jordan also spoke at the event.