WASHINGTON, March 28 (Reuters) - The United States has not seen any indications that Vladimir Putin is getting closer to using tactical nuclear weapons in his war on Ukraine, just days after the Russian leader said he was moving such weapons into Belarus.

"We're watching this as best we can. We haven't seen any movement by Mr. Putin to act on what he pledged he would do," White House spokesperson John Kirby told reporters about Putin's statement on Belarus.

"And we haven't seen any indications that Mr. Putin is leaning towards or getting closer to or indicating any preparations for the use of tactical nuclear weapons in Ukraine."