First Thing: Democrats torn over Biden amid concern deepens over whether he can win

Seven House Democrats have so far called for president to quit. Plus, Israeli strike on Khan Younis shelter kills at least 25

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Good morning.

After a day of private meetings on Capitol Hill, congressional Democrats appeared torn over whether Joe Biden should remain the party's nominee, as concerns deepen over the 81-year-old president's age, mental acuity and ability to win the White House for a second term.

Who has affirmed their support of Biden? Most prominent Democrats: the vice-president, Kamala Harris; Schumer, the Senate majority leader; the South Carolina representative James Clyburn; senior members of the Black and Hispanic caucuses; and progressives including Alexandria Ocasio-Cortez and Ilhan Omar.

What did Biden say in his Nato speech? On Tuesday, in Biden's headline speech - a critical step to convincing foreign leaders he remains up to the task - the president said in forceful tones: Today, Nato is stronger than it's ever been in its history."

What's the latest on ceasefire negotiations? Mediation efforts led by Egypt, Qatar and the US continue, with Egyptian media reporting that talks are due to continue in Doha and Cairo this week, attended by the CIA director and Israel's Mossad chief.

What effect is latest wave of attacks having on the talks? On Monday night, Hamas's Qatar-based political chief, Ismail Haniyeh, said that the catastrophic consequences" of the latest battles on the ground in Gaza could reset the negotiation process to square one".