WRAPUP 11-Ukraine pleads for more weapons, chief negotiator sees turning point in war

(Adds comments from Ukrainian chief negotiator, Zelenskiy travel)

* Barrages pepper Donbas as defenders dig in

* G20 urges Russia to unblock grain exports

* Putin warns of 'catastrophic' energy price spikes

By Pavel Polityuk

KYIV, July 8 (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.