(Reuters) - U.S. Republican Senator Lindsey Graham called Ukraine's shock cross-border operation into Russia's Kursk region "brilliant" and "bold" in a visit to Kyiv on Monday, and he urged the Biden administration to provide Ukraine with the weapons it needs.

With Russia still struggling to repel the Ukrainian incursion seven days after it began, Ukraine's top commander said Kyiv controlled around 1,000 square kilometers in the Kursk region.

Graham made comments during a visit to Kyiv with Democratic Senator Richard Blumenthal.

"What do I think about Kursk? Bold, brilliant, beautiful. Keep it up," he told reporters.

"Bottom line is to the administration. ... Give them weapons they need to win the war they can't afford to lose," he added.

During the meeting with the Senate delegation, President Volodymyr Zelenskiy thanked the U.S. for support.

"We discussed what exactly is needed to bring this war to a just end, including our need to use long-range weapons," he said later in a post on X.

(Reporting by Sergiy Voloshyn; Writing by Yuliia Dysa; Editing by Leslie Adler)