NATO allies reiterated their commitment to collective security on Monday after Donald Trump suggested he’d abandon members who are delinquent in paying their membership dues. Alliance members agreed to pay a minimum amount after being rocked by Trump questioning U.S. participation when he was president due to what he considered an unfair financial burden. But even some fellow Republicans think the presumptive nominee for the presidential election has gone too far.

Owen Fairclough reports from Washington D.C.