Jordan’s king has warned Israel of a “massive conflict” if it proceeds with plans to annex large parts of the occupied West Bank.

“Leaders who advocate a one-state solution do not understand what that would mean,” Jordan’s King Abdullah II said in an interview with the German magazine Der Spiegel published Friday.

“What would happen if the Palestinian National Authority collapsed? There would be more chaos and extremism in the region. If Israel really annexed the West Bank in July, it would lead to a massive conflict with the Hashemite Kingdom of Jordan,” he said.

Jordan is a close Western ally and one of only two Arab states to have signed a peace treaty with Israel. Abdullah declined to say whether annexation would threaten that agreement.

“I don’t want to make threats and create an atmosphere of loggerheads, but we are considering all options. We agree with many countries in Europe and the international community that the law of strength should not apply in the Middle East.”

Israeli leaders have vowed to annex Jewish settlements and the Jordan Valley, which could spell the end of the long-stalled peace process by making it virtually impossible to establish a viable Palestinian state.

President Donald Trump’s Middle East plan, which overwhelmingly favors Israel and was rejected by the Palestinians, gave a green light to annexation, but the majority of the international community is strongly opposed.