By Pavel Polityuk
KYIV (Reuters) - Ukraine urged its allies on Friday to send more weapons as its forces dug in to slow Russia's military advance through the eastern Donbas region, while its chief negotiator said a turning part was approaching in the conflict.
Signalling that the Kremlin was in no mood for compromise, President Vladimir Putin said continued use of sanctions against Russia for the invasion it launched in February risked causing "catastrophic" energy price rises.
His top diplomat, Sergei Lavrov, clashed with his Western counterparts at a G20 meeting, where they urged Russia to allow Kyiv to ship blockaded Ukrainian grain out to an increasingly hungry world.
Meanwhile, Moscow's envoy to London offered little prospect of a pull-back from parts of Ukraine under Russian control.
Ambassador Andrei Kelin told Reuters that Russian troops would capture the rest of Donbas in eastern Ukraine and were unlikely to withdraw from land across the southern coast.
Ukraine would eventually have to strike a peace deal or "continue slipping down this hill" to ruin, he said.
On the Donbas frontlines, Ukrainian officials reported Russian shelling of towns and villages ahead of an anticipated push for more territory.
A Ukrainian infantry unit on the road to the town of Siversk, whose members spoke to Reuters, had set up positions on the edge of a deep earth bunker covered with logs and sandbags and defended by machine guns.
In the Russian-occupied parts of the Kherson and Zaporizhzhia regions in southern Ukraine, meanwhile, residents were urged to evacuate by the Ukrainian deputy prime minister in order to allow Ukrainian forces to launch a counter-offensive.
"Please leave - our army will begin retaking these areas. Our determination is rock solid. And it will be very difficult later to open humanitarian corridors when children are involved," said Iryna Vereshchuk, quoted in Ukrainian media.
Ukrainian President Volodymyr Zelenskiy went on a visit to areas at and near the front, and said he spent the day visiting a hospital in Dnipro treating wounded soldiers and touring areas in the forward lines of defence in Dnipropetrovsk and Kriviy Rih regions.
Mykhailo Podolyak, the Ukrainian chief negotiator in stalled talks with Russia, said a turning point was starting to take shape as Russian forces were forced to take an operational pause due to losses and to resupply.
"It is clear that they have to redeploy things, bring forward new troops and weaponry, and this is very good. A certain turning point is beginning to take shape because we are proving we are going to attack storage facilities and command centres," Podolyak told Ukraine's 24 Channel television.
'SCORCHED EARTH TACTICS'
On Thursday, Putin had indicated that current prospects of finding a solution to the conflict were dim, saying Russia's campaign in Ukraine had barely started.
Ambassador Kelin's remarks gave an insight into Russia's potential endgame - a forced partition that would leave its former Soviet neighbour shorn of more than a fifth of its post-Soviet territory.
An escalation of the war was possible, Kelin said.
Ukrainian officials, echoing comments by the deputy commander of the infantry unit outside Siversk, said they needed more high-grade Western weapons to shore up the their defences.
U.S. President Joe Biden signed a new weapons package worth up to $400 million for Ukraine on Friday, including four additional high mobility artillery rocket systems (HIMARS) and more ammunition.
Zelenskiy on Twitter thanked Biden for the HIMARS and shells, which he said were priority needs.
"It is what helps us press on the enemy," he said.
The United States started providing the key precision rocket weapon system to Ukraine last month after receiving assurances from Kyiv that it would not use them to hit targets inside Russian territory. Kyiv has attributed battlefield successes to the arrival of the HIMARS.
"When they came in, the Russian war machine could instantly feel its effect," Oleksiy Danilov, secretary of the National Security and Defence Council, told Reuters. But more Western military aid was vital, he added.
'NOT YOUR COUNTRY'
At the G20 meeting in Bali, Indonesia, some of the staunchest critics of the invasion confronted Lavrov, who walked out of a meeting and denounced the West for "frenzied criticism."
High on the list of foreign ministers' concerns was getting grain shipments from Ukraine out through ports blocked by Russia's presence in the Black Sea and naval mines. Ukraine is a leading exporter and aid agencies have warned that many developing countries face devastating food shortages if supplies fail to reach them.
U.S. Secretary of State Antony Blinken urged Moscow to let Ukrainian grain out, a Western official said.
"He addressed Russia directly, saying: 'To our Russian colleagues: Ukraine is not your country. Its grain is not your grain. Why are you blocking the ports? You should let the grain out,'" the official said.
Since Russia started in February what it calls a special operation to demilitarize Ukraine, cities have been bombed to rubble, thousands have been killed, and millions displaced.
Ukraine and its Western allies say Russia is engaged in an unprovoked land grab.
Russian forces have seized a big chunk of territory across Ukraine's southern flank and are waging a war of attrition in the Donbas, the eastern industrial heartland made up of Luhansk and Donetsk provinces.
Luhansk's governor said Russian forces were indiscriminately shelling populated areas on Friday.
"They are not stopped even by the fact that civilians remain there, dying in houses and yards," Serhiy Gaidai said.
Reuters could not independently verify battlefield accounts.
In the city of Sievierodonetsk, which was fully occupied by Russian forces last month, most of the infrastructure has been destroyed and major repairs are needed, said Oleskandr Stryuk, the mayor, warning that sanitation in the meantime will be "catastrophic."
(Reporting by Reuters bureaux; Writing by Angus MacSwan, John Stonestreet and Daphne Psaledakis; Editing by Frank Jack Daniel, Tomasz Janowski and Rosalba O'Brien)