United Nations Secretary-General Antonio Guterres on Monday said that Israel's creeping annexation of the West Bank is illegal, and the wholesale destruction of the Gaza Strip is intolerable, and both must stop.

"Let's be clear: The creeping annexation of the occupied West Bank is illegal. It must stop. The wholesale destruction of Gaza is intolerable. It must stop," he told a conference at the U.N. on a two-state solution between Israel and the Palestinians.

"Unilateral actions that would forever undermine the two-state solution are unacceptable. They must stop," Guterres said.