L ONDON -- Ukrainian President Volodymyr Zelenskyy's top adviser urged the U.S. to "strangle" Russia's economy by imposing secondary sanctions on Moscow's trading partners, as the White House push for a ceasefire appears to languish.

U.S. President Donald Trump has made clear that he wants a deal to end Russia’s war in Ukraine by August 8, the United States told the United Nations Security Council on Thursday. “Both Russia and Ukraine must negotiate a ceasefire and durable peace.