BRUSSELS (Reuters) - Russian President Vladimir Putin is in no position to make demands on Ukraine to end the war, U.S. Defense Secretary Lloyd Austin said on Friday, as he touted Kyiv's military successes confronting Moscow's full-scale invasion.

Putin said earlier on Friday that Russia would end the war in Ukraine only if Kyiv agreed to drop its NATO ambitions, hand over the entirety of four provinces claimed by Moscow, and carry out a demilitarization.

"He is not in any position to dictate to Ukraine what they must do to bring about peace," Austin told reporters at NATO headquarters in Brussels.

Russia controls nearly a fifth of Ukrainian territory in the third year of the war. Ukraine says peace can only be based on the full withdrawal of Russian forces and the restoration of its territorial integrity.

"He's had some hundreds of thousands of troops wounded and killed in this unjust and unprovoked invasion. He could end this today if he if he chose to do that. And we call upon him to do that and to leave Ukrainian sovereign territory," Austin said.

In his address, Putin said "the future existence of Ukraine" depended on it withdrawing its forces, on it adopting a neutral status, and on beginning talks with Russia, and said Kyiv's military situation would worsen if it rejected the offer.

The timing of Putin's speech was clearly intended to preempt Ukraine's Swiss summit, billed as a "peace conference" despite Russia's exclusion, where Ukrainian President Volodymyr Zelenskiy seeks a show of international support for Kyiv's terms to end the war. His remarks also came ahead of NATO's summit in Washington, in which Ukraine's allies are also still at odds over whether and how to strengthen NATO's wording on Ukraine's future membership in the alliance.

NATO's official line is that Ukraine will join the alliance one day, but not while the country is at war. "Ukraine's future is in NATO," NATO leaders declared at last year's Vilnius summit.

Some allies want this language to be strengthened, suggesting the summit declare that Ukraine's path to membership is "irreversible", according to diplomats.

Austin sidestepped the issue, saying only that NATO expansion wasn't likely in the short-term.

"In terms of NATO expansion, I think that's a decision that 32 members of (the) NATO alliance will make at some point in time, I don't see any desire or indication that we will pursue expansion at any point in the near future," Austin said.

Austin said he suspected there would always be countries that would want to join NATO, but at this point the alliance wants to focus on bringing on its newest member, Sweden and Finland.

"I think at this point in time, the members of the alliance would probably want to see things stabilize and settle out as we get the new members on board and continue to refine our plans," Austin said.

(Reporting by Sabine Siebold in Brussels, Phil Stewart and Idrees Ali in Washington; Writing by Phil Stewart; Editing by Chizu Nomiyama)

By Sabine Siebold, Idrees Ali and Phil Stewart