U.S. President Joe Biden has hailed Ukraine's retaking of the city of Kherson as a "significant victory," raising confidence that Moscow will not occupy its neighbor as intended when it invaded in late February.
The liberation of Kherson over the weekend was one of Ukraine's biggest successes in nearly nine months since the start of the Russian invasion.
Biden commented on the development during a press conference after meeting with Chinese President Xi Jinping on the sidelines of the Group of 20 (G20) summit in Bali, Indonesia.
"I can do nothing but applaud the courage, determination, and capacity of the Ukrainian people," he said. "I think you are going to see things slow down a bit because of the winter months.... I think it remains to be seen exactly what the outcome will be."
Biden also raised Russia's "irresponsible threats of nuclear use," according to a White House readout on the meeting.
"President Biden and President Xi reiterated their agreement that a nuclear war should never be fought and can never be won and underscored their opposition to the use or threat of use of nuclear weapons in Ukraine," the statement said.
Separately, CIA Director Bill Burns met in Ankara, Turkey, on November 14 with Russian intelligence chief Sergei Naryshkin, the head of Russia's Foreign Intelligence Service (SVR).
Burns underscored the consequences if Russia were to deploy a nuclear weapon in Ukraine, according to a White House National Security Council official who spoke on the condition of anonymity.
"He is not conducting negotiations of any kind. He is not discussing settlement of the war in Ukraine," the White House official said. "He is conveying a message on the consequences of the use of nuclear weapons by Russia, and the risks of escalation to strategic stability."
Russian officials have alarmed Western governments by raising the potential use of tactical nuclear weapons after suffering massive setbacks in Ukraine.
The official quoted said there had been no change in the U.S. intelligence assessment and declined to offer further detail on timing of the decision to send Burns to meet with Naryshkin.
The Burns-Naryshkin meeting was the highest-ranking face-to-face engagement between U.S. and Russian officials since before Russian President Vladimir Putin ordered the invasion.
Burns was also expected to raise the cases of Brittney Griner and Paul Whelan, two Americans detained in Russia. Washington has pressed Moscow to release the two in a prisoner exchange.
Kremlin spokesman Dmitry Peskov said earlier on November 14 that he could neither confirm nor deny reports of U.S.-Russia talks in Turkey.
