President Vladimir Putin has blasted the West for trying to "tear apart" Russia and said in an interview aired on national television that his offensive in Ukraine aimed to "unite the Russian people".
Meanwhile in Kyiv, a day after deadly shelling in southern Ukraine, residents held Christmas services on Sunday, defying Russian spiritual leaders who celebrate it on January 7.
He said Russia's "geopolitical opponents (were) aiming to tear apart Russia, the historical Russia".
"Divide and conquer, that's what they have always sought to accomplish and are still seeking to do," Putin added.
"But our goal is different: it's to unite the Russian people," he said.
Putin declared his government was acting "in the right direction... protecting our national interests, the interests of our citizens, of our people."
He repeated that Moscow was ready to negotiate and appeared unfazed when asked about the new air defence system the United States will deliver to Ukraine.
- Kherson 'terror' -
Earlier this week, in his first trip outside Ukraine since the offensive began, Zelensky earned firm pledges of support from US President Joe Biden, including the Pentagon's most advanced air defence system.
Western military and financial aid has been crucial for Ukraine's pushback of Russian troops -- including from Kherson, the only regional capital that was held by Russia.
Despite Russia's retreat from the city, it remains within reach of Moscow's weaponry and under constant threat.
The Ukrainian army counted 71 strikes on the partly recaptured Kherson region on Saturday, including 41 on the city.
This included deadly shelling on a busy market in the city centre that left 10 people dead and 55 injured.
The Russian-installed head of the Kherson region, Vladimir Saldo, said on Telegram the shelling was "a disgusting provocation" by Ukraine used to blame Russia.
In his daily address on Sunday, Zelensky condemned Russian "terrorists" and thanked all his compatriots -- including soldiers, doctors, volunteers -- involved in defending Ukraine.
"Thank you... to everyone who came to Kherson to help. To save the wounded from the terrorists' strike on Christmas. Artillery and mortar against ordinary Kherson streets... monsters!" Zelensky said.
- Defiant Christmas -
On Sunday, church bells pealed throughout Kyiv as Orthodox Christians attended Christmas services, in break with the Russian spiritual leaders who will mark the holiday in two weeks.
At a service in central Kyiv, worshipper Olga Stanko told AFP she supported any move that would distance Ukraine from Russia.
"The war has brought us so much grief," she said. "We cannot do this with Russia, remain under its influence."
Also attending the service, Olena Zakharova-Gorianska said she was happy to be celebrating Christmas on December 25 for the first time -- describing it as an obvious choice after surviving Russian occupation in the town of Gostomel, north of Kyiv.
"I do not want to have anything to do with the occupiers, with the enemy," she said.
The decision by some Ukrainian churches to observe Christmas on December 25 highlights the deepening rift between religious leaders in Kyiv and Moscow.
An Interfax-Ukraine poll showed an increasing number in favour of moving the Christian holy day to December 25, jumping from 26 percent in 2021 to 44 percent in 2022, though 31 percent were still against it.
Ukraine had been under Moscow's spiritual leadership since at least the 17th century, but part of the Ukrainian Orthodox Church broke with Moscow in 2019 over Russia's annexation of Crimea and support for separatists in the east.
In May, the Russia-backed branch of Ukraine's Orthodox Church also severed ties with Moscow.
From the St Peter's Basilica at the Vatican, Pope Francis called for an end to the conflict.
"May the Lord... enlighten the minds of those who have the power to silence the thunder of weapons and put an immediate end to this senseless war!" the Argentine pontiff said.