A key architect of the long-awaited U.S. plan for Israeli-Palestinian peace is warning that "nothing can be meaningfully fixed" until Gaza's Hamas rulers and Palestinian Islamic Jihad renounce their vows to destroy Israel and stop carrying out violent acts.

Jason Greenblatt, President Donald Trump's envoy of international negotiations, also told the Security Council "it would be a mistake" for the Palestinians not to attend a conference in June that is part of the rollout of the White House plan, saying they have "much to gain." The Palestinian Authority said it will not attend.

Greenblatt also lashed out at the U.N. agency that helps 5.3 million Palestinian refugees, calling it "a band-aid" that is "running on fumes." He reiterated a previously rejected U.S. proposal for host countries or non-governmental agencies to take over services.