The United States will suspend the planned export of hundreds of air defense munitions to its allies and partners and redirect them to Ukraine, the White House said Thursday, as Russia continues its assault on the country’s power grid and other vital infrastructure.

       Speaking to reporters, National Security Council spokesman John Kirby characterized the decision as “difficult but necessary,” and said it would affect deliveries of Patriot and NASAMS interceptor missiles, principally. Ukraine, he said, faces a “desperate” need.