US Secretary of State Blinken says Russia turmoil could take months to play out

The unprecedented challenge to Russian President Vladimir Putin by Wagner fighters has exposed fresh "cracks" in the strength of his leadership that may take weeks or months to play out, US Secretary of State Antony Blinken said on Sunday.

"I don't think we've seen the final act," Blinken said on ABC News, in one of a series of interviews after an aborted mutiny by forces led by Yevgeny Prigozhin.

Blinken said tensions that sparked the action had been rising for months and the turmoil could affect Moscow's military capabilities in Ukraine.

"We've seen more cracks emerge in the Russian facade. It is too soon to tell exactly where they go, and when they get there. But certainly, we have all sorts of new questions that Putin is going to have to address in the weeks and months ahead," Blinken told NBC's "Meet the Press" program.

Blinken described the turmoil as an "internal matter" for Putin.

"Our focus is resolutely and relentlessly on Ukraine, making sure that it has what it needs to defend itself and to take back territory that Russia seized," Blinken said.

US officials expect to learn more in coming days and weeks about the events that unfolded in Russia, including details of the deal with Prigozhin mediated by Belarusian President Alexander Lukashenko that led Wagner fighters to return to their bases.

"It may be that Putin didn't want to debase himself to the level of negotiating directly with Prigozhin," Blinken said.

Forces led by Prigozhin, a former Putin ally and conflict, have fought the bloodiest of battles in Russia's 16-month war in Ukraine.

"To the extent that the Russians are distracted and divided it may make their prosecution of aggression against Ukraine more difficult," Blinken told ABC's "This Week" program.

Blinken said neither the United States nor the Russian nuclear posture had changed as a result of the crisis.

US Senator Ben Cardin said the weekend turmoil in Russia does not ease Washington's need to continue aiding Ukraine as it launches its long-awaited counteroffensive against Russia.

"This is a critical time for Ukraine. This counteroffensive is going to be defining as to where we're going to be in the next year or two," Cardin, a Democrat who sits on the Senate Foreign Relations Committee, told Fox News. "So it's incredibly important that we maintain our support and not be fooled by what's happening in Russia today as to the needs of the Ukrainians."