Trump Wades Into Gaza Diplomacy as Israeli Military Moves on Gaza City

President Trump’s latest foray into Middle East peacemaking presented Hamas with what sounded like an ultimatum. He effectively pressed the Palestinian militant group to either accept a new American cease-fire proposal or face the full wrath of Israel’s military advance into Gaza City.

“The Israelis have accepted my Terms,” Mr. Trump posted on social media on Sunday, hinting at a new American proposal to exchange all the remaining hostages for Palestinian prisoners and end the nearly two-year-old Gaza war. “It is time for Hamas to accept as well.”

“I have warned Hamas about the consequences of not accepting,” Mr. Trump said. “This is my last warning...