U.S. President Joe Biden and his Ukrainian counterpart Volodymyr Zelensky on Sunday discussed recent developments in Russia a day after the armed rebellion staged by the Wagner group mercenary boss. 

“We discussed the course of hostilities and the processes taking place in Russia. The world must put pressure on Russia until international order is restored,” Zelensky said on Twitter. 

Earlier on Friday, the Wagner group chief Yevgeny Prigozhin launched an armed revolt and captured several cities on his way to Moscow to oust Russia’s Defense Minister Sergei Shoigu. However, on Saturday evening he suddenly announced that his troops were turning back after reaching an agreement with authorities mediated by Belarus’ President Alexander Lukashenko. 

Both Kiev and Washington said that despite the immediate threat to Putin’s rule being averted, the revolt showed the weakness of the Russian leadership. 

Zelensky also said on Twitter that he had a “positive and inspiring conversation” with Biden and thanked him for the “unflagging” support of Ukraine. He added that they discussed the “further expansion of defense cooperation,” including long-range weapons, and Ukraine’s capabilities to “protect” their skies.

The White House in turn said that Biden and Zelensky discussed Ukraine’s ongoing counter-offensive, “and President Biden reaffirmed unwavering U.S. support, including through continued security, economic, and humanitarian aid.”

“The leaders also discussed recent events in Russia,” the statement said.