A damaging week has widened the rift between the United States and Ukraine, with President Donald Trump and President Volodymyr Zelensky trading public criticism and US threats to cut intelligence support raising fears for Kyiv.

Trump, frustrated by high energy prices he blames partly on Ukrainian strikes on Russian refineries, has repeatedly criticised Zelensky. He waived key Russia-related sanctions and tariffs on Friday, shortly before they were due to take effect under the Graham Act, saying the move was in the US national interest.

Zelensky responded sharply, saying the United States now appeared to favour Russia and that Ukraine would not stop striking Russian energy targets. "Financial rewards for Putin - all of this only encourages him to keep attacking," he wrote on X.

The waiver drew condemnation from both parties in the US Congress. Republican Senator Thom Tillis called it "beyond irresponsible", while Democratic Senator Elizabeth Warren accused Trump of "thumbing his nose" at Congress.

US officials had warned Ukrainian commanders that battlefield intelligence could be reduced or cut off, Zelensky told NPR. Ukraine's Starshield system, the military-grade version of SpaceX's Starlink, was briefly disrupted by an order originating in the White House, according to US and Western officials cited by Reuters.

Trump said the United States is still sharing intelligence and that he would keep dealing with both Zelensky and Russian President Vladimir Putin. "I want that war to end," he told reporters.

Analysts warn that a further drawdown of US support would leave Ukraine more exposed to Russian strikes on its energy infrastructure as winter approaches. Kyiv is still seeking talks through Trump's envoys, Steve Witkoff and Jared Kushner, Ukrainian officials said.