WASHINGTON, July 26 (Reuters) - Ukraine's counteroffensive is "not a stalemate" even if it is not progressing fast enough, White House national security spokesman John Kirby told reporters on Wednesday.

Kirby made the remarks when asked about the pace of Ukraine's counteroffensive in a press briefing.

"President Zelenskiy himself has said that he that it's not progressing as fast as he would like and they're not moving as far every day as they would like. The United States is not going to take a position on that," Kirby said.

He added: "That said they are moving, it's not a stalemate. They're not just frozen. The Ukrainians are moving."

The White House national security spokesman said Washington would "make sure that they (Ukrainians) have the kinds of tools and capabilities they need to stay on the move."

More than $43 billion in U.S. military aid has been provided since Russia's invasion began in February 2022. The U.S. Department of Defense announced $400 million in additional security assistance for Ukraine earlier this week, including air defense missiles, armored vehicles and small drones.

U.S. Secretary of State Antony Blinken said on Sunday that while Ukraine has recaptured half the territory that Russia initially seized in its invasion, the counteroffensive was in its early days and would take shape over "several months."