The United States will soon send one of its largest-ever security assistance packages to Taiwan — nearly $570 million — the White House said late Monday in a move sure to anger China.

Washington, Taipei’s biggest and most important backer despite a lack of bilateral ties, will use its fastest tool available to deliver the aid to Taiwan, as the democratic island grapples with ramped-up military moves by China in the waters and airspace nearby.

Beijing — which claims Taiwan as a renegade province and has vowed to unify the island with the mainland, by force if necessary — has steadfastly demanded that Washington halt weapons sales to Taipei.