First Thing: Mike Waltz takes ‘full responsibility’ for Signal chat gaffe

National security adviser accepts he made the group but deflects blame. Plus, the definitive guide on getting over a grudge

• Don't already get First Thing in your inbox? Sign up here

Good morning.

Donald Trump's national security adviser, Michael Waltz, has said he accepts full responsibility" for creating the group chat of top security officials that leaked highly sensitive information about imminent strikes in Yemen after accidentally including a journalist.

How has the leak been received internationally? Mostly with shock (and a fair amount of ridicule) - but it has also led Canada's prime minister, Mark Carney, to warn that Five Eyes allies must look out for ourselves".

What has Russia said? The Kremlin's line is that a ban on striking energy targets is in place - but that the Black Sea security deal, agreed on Tuesday, will first require the lifting of sanctions.