President Donald J. Trump spoke yesterday with Prime Minister Theresa May of the United Kingdom. The leaders agreed that the Syrian regime and its Russian and Iranian sponsors must immediately and fully implement United Nations Security Council Resolution 2401, which calls for an immediate ceasefire across Syria. The leaders condemned sharply the bombing in East Ghouta. They affirmed that the United States and United Kingdom will hold Russia accountable for compelling the Assad regime to halt attacks against civilian areas and for granting access to humanitarian relief in East Ghouta. The leaders agreed that Russian President Vladimir Putin’s recent statements on nuclear weapons development were irresponsible. President Trump and Prime Minister May discussed other topics, including President Trump’s efforts to ensure fair and reciprocal trade as well as Prime Minister May’s work on Brexit negotiations.