Pakistan, Oct. 18 -- From US threats to cut off intelligence support for Ukraine to a diesel deal that could help Russia fund its war, it has been a damaging week for ties between Kyiv and its most important ally, Washington.

Frustrated by high energy costs he blames partly on Ukrainian strikes on Russian refineries, US President Donald Trump has repeatedly criticized Ukrainian President Volodymyr Zelenskiy. A disruption of US-provided satellite internet services raised fears that Ukraine could be vulnerable as it prepares for another winter of Russian attacks on its energy infrastructure.

Zelenskiy responded to Trump's barbs with an unusually sharp series of public criticisms of Trump, suggesting the US was now favoring Russia. He said...