By Jonathan Landay and Jonathan Spicer
KHERSON, Ukraine/ANKARA (Reuters) - Ukrainian President Volodymyr Zelenskiy on Monday visited Kherson, the biggest prize his troops have recaptured so far, vowing to press on until Kyiv reclaims control of all its occupied territory.
Zelenskiy's visit came as the heads of U.S. and Russian intelligence met in Turkey for the highest level publicly acknowledged face-to-face talks between the two countries since the Russian invasion of Ukraine in February.
Washington said Kyiv was aware of the meeting, meant to prevent an inadvertent escalation but not involve discussion of any settlement.
Zelenskiy shook hands with soldiers and waved to civilians looking out from surrounding flats as he was escorted by bodyguards three days after his troops swept into the city.
He told soldiers they had "proved it was impossible to kill Ukraine", then held a minute's silence for the dead.
Residents also turned out, parading blue-and-yellow flags and chanting "Kherson is Ukraine" - a contrast with the early days of the occupation when people berated Russian soldiers.
No senior Russian official had made an analogous visit during eight months of occupation of the city, which President Vladimir Putin proclaimed "eternally Russian" six weeks ago.
Zelenskiy said Ukraine was ready for peace, but only with the restoration of all occupied territory: "You see our strong army. We are step-by-step coming through our country, through the temporarily occupied territories."
Minutes before he arrived, nearby shelling could be heard. After he finished speaking, blasts of artillery echoed.
'PEOPLE WERE SMILING'
Russia pulled all its troops out of a pocket on the west bank of the Dnipro River last week, which included Kherson city, the only regional capital it had captured since the invasion.
Olga Fedorova, an English teacher in Kherson throughout the occupation, said lack of electricity or mobile internet connection meant many were unaware of events until Ukrainian troops raised their flag in the main square on Nov. 11.
"We just understood that there are no Russian troops in this city and something has changed," she said.
"People were smiling and probably somebody knew something. And then when we returned, we saw how the flag was raised by our people. And we were just crying."
Zelenskiy said Ukraine had gathered evidence of at least 400 war crimes committed by Russian troops during their occupation of the area, including killings and abductions.
They left corpses, broken infrastructure and landmines littered behind them, he said. "The Russian army left behind the same savagery it did in other regions," he said in an overnight televised address.
Russia denies its troops target civilians or have committed atrocities. Mass burial sites have been found in other parts previously occupied by Russian troops, including some with civilian bodies showing signs of torture.
Residents in and around Kherson interviewed by Reuters since Friday have described killings and abductions.
Russian soldiers "would approach you in the street and ask if you were Ukrainian or Russian. If you said Ukrainian, they would take you away," Natalia Papernaya, a 43-year-old clothing designer, said on Sunday.
The Russians, she said, had arrested her friend for photographing a neighbour's home to reassure the owners it had survived a nearby shell blast. The troops had taped her friend's hood over her eyes, put her in a cellar for a day and demanded to know for whom she was taking pictures.
The friend was unharmed but heard other detainees screaming or shouting out praise for Putin under duress.
"There were many people in there, women and men," she said.
Reuters reported one account of a neighbour shot dead and three accounts of people carried off by troops in the village of Blahodatne north of Kherson.
It was not possible to verify the accounts independently.
There were reports of fierce clashes and artillery bombardments elsewhere to the north and east along the front lines that stretch more than 1,000 km (620 miles).
"The enemy is attempting to hold temporarily occupied territory and is continuing to equip areas on the east bank of the Dnipro River," Ukraine's armed forces' general staff said in a Facebook post on Monday evening.
"It is maintaining its offensive actions near Bakhmut and Avdiivka," the statement added, referring to areas in eastern Donetsk region where the heaviest fighting has been taking place.
Russia's defence ministry was quoted by RIA news agency as saying its forces had taken the village of Pavlivka in Donetsk.
Neither sides' accounts could be independently confirmed.
A White House spokesperson said CIA Director William Burns' meeting in Turkey with Russian foreign intelligence chief Sergei Naryshkin was meant to convey the consequences should Putin use nuclear weapons.
"He is not conducting negotiations of any kind," said the spokesperson. "He is conveying a message on the consequences of the use of nuclear weapons by Russia, and the risks of escalation to strategic stability. He will also raise the cases of unjustly detained US citizens."
The Kremlin confirmed a U.S.-Russia meeting had taken place in Ankara but declined to give details.
Putin has repeatedly suggested Russia could use nuclear weapons to defend its territorial integrity, interpreted in the West as an implicit threat to use them over lands Moscow claims to have annexed.
(Reporting by David Ljunggren, Jonathan Landay, Gleb Garanich, Pavel Polityuk, Ron Popeski, Joseph Campbell and Felix Hoske; Writing by Philippa Fletcher and Alex Richardson; Editing by Peter Graff and Andrew Cawthorne)