Ukrainian forces pressed ahead with their counteroffensive to liberate Moscow-occupied territories, handing Russian forces a series of defeats that have prompted U.S. President Joe Biden to warn the threat of the Kremlin using nuclear weapons was the highest in six decades.
Russian President Vladimir Putin has made thinly veiled threats to use his nuclear arsenal in Ukraine, and Biden told U.S. media on October 6 that Putin was "not joking."
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"We have not faced the prospect of Armageddon since [the time of U.S. President John F.] Kennedy and the Cuban missile crisis" in 1962, Biden said in New York, adding that "we're trying to figure out what is Putin's off-ramp."
In 1962, the United States under Kennedy and the Soviet Union under its leader, Nikita Khrushchev, came close to using nuclear weapons over the presence of Soviet missiles in Cuba.
Russia last week officially incorporated four Ukrainian regions that it only partially controls in a move that violated international law, and Putin, who marks his 70th birthday on October 7, said Moscow would see Ukrainian attacks on those regions as attacks on Russia itself and would use all means to defend them.
The move came amid rapid Ukrainian advances, with President Volodymyr Zelenskiy announcing on October 6 more wins in Kherson, one of the four regions claimed by Moscow.
"More than 500 square kilometers have been liberated from Russian occupiers in the Kherson region alone" since the start of the month, Zelenskiy announced in his nightly address.
The recaptured territory was home to dozens of towns and villages that had been occupied by Russian forces for months, southern army command spokeswoman Natalia Gumeniuk said.
Kherson, a region with an estimated prewar population of around 1 million people, was captured early and easily by Moscow's troops after their invasion launched on February 24.
Zelenskiy said Ukrainian forces were also advancing in Donetsk and Luhansk in the east and voiced optimism about recapturing territory lost in the southeast in Zaporyzhzhya -- the fourth of the regions illegally declared by Moscow as part of the Russian Federation.
"There are successes in the east as well. The day will surely come when we will report on successes in the Zaporyzhzhya region as well, in those areas that the occupiers still control," the president said.
The claims could not be independently verified.
Russian forces, meanwhile, struck the city of Zaporyzhzhya again on October 6. A missile demolished an apartment block and killed 11 people in the city, the emergency services said.
SEE ALSO: European Leaders Hold Inaugural Meeting Of New Forum In Context Of War In UkraineIn a separate video address to a new security and energy cooperation forum gathered in Prague, Zelenskiy accused Russia of deliberately targeting the same spot twice in succession.
"In Zaporyzhzhya, after the first rocket strike today, when people came to pick apart the rubble, Russia conducted a second rocket strike. Absolute vileness, absolute evil," he told the European Political Community.
Moscow says it does not deliberately target civilians.
In the Kharkiv region in the northeast, a Ukrainian general said on October 6 that Kyiv's forces had advanced up to about 55 kilometers over the past two weeks.
In the eastern Donetsk region, the Ukrainian General Staff said Russian troops had blown up a dam near the city of Slavyansk as they withdrew, inundating the nearby town of Rayhorodok.
SEE ALSO: In Eastern Ukraine, Survivors Of A Deadly Ambush Recall Their Desperate EscapeThe report could not be independently confirmed.
As Ukrainian forces continued to make advances into several of the four regions seized by Moscow, a senior Russian lawmaker called on military officials to tell the truth about developments on the ground.
"We need to stop lying," the chairman of the lower house of parliament's defense committee, Andrei Kartapolov, told a journalist from state-run media.
"The reports of the Defense Ministry do not change. The people know. Our people are not stupid. This can lead to loss of credibility."