Thanks very much for reading Need to Know this Sunday, March 24. Here are the biggest developments of the day so far:

Biden and Trump win Louisiana’s presidential primaries President Joe Biden and former president Donald Trump won Louisiana’s primaries on Saturday (Sunday AEDT), collecting more delegates after they already clinched their party nominations.

US proposes hostage-to-prisoner ratio in Gaza truce talks The United States has made a “bridging proposal” for the number of jailed Palestinians to be released by Israel in exchange for every hostage freed by Hamas in any new Gaza truce, an Israeli official briefed on the Qatar-hosted talks said on Saturday (Sunday AEDT).

AUKUS costs are not blowing out: Marles Deputy Prime Minister Richard Marles says the cost of acquiring nuclear-powered submarines under AUKUS is still running within budget.

Labor confident Trump will back AUKUS if he wins Deputy Prime Minister Richard Marles says the Albanese government is confident Republicans will support AUKUS if Donald Trump wins the November 2024 US election.