By Mukhammadsharif Mamatkulov and Max Hunder
SAMARKAND, Uzbekistan/KYIV (Reuters) - Russian President Vladimir Putin said on Thursday he understood China's Xi Jinping had concerns about the crisis in Ukraine, a surprise acknowledgement of friction with Beijing over the war after a week of stunning Russian losses on the ground.
Since Russia invaded Ukraine in February, China has trod a careful line, criticising Western sanctions against Moscow but stopping short of endorsing or assisting in the military campaign.
"We highly value the balanced position of our Chinese friends when it comes to the Ukraine crisis," Putin told Xi at their first meeting since the war began.
"We understand your questions and concern about this. During today's meeting, we will of course explain our position."
Xi did not mention Ukraine in his public remarks, nor was it mentioned in a Chinese account of the meeting, which took place in Uzbekistan on the sidelines of a regional summit.
Beijing's support is widely seen as essential for Moscow, which needs markets for its energy exports and sources to import high tech goods while sanctions are imposed by the West.
The Russian president's comments suggested a Chinese shift towards a more critical stance, in private at least. Ian Bremmer, political science professor at Columbia University, said they were the first public sign of Putin recognising pressure to back down.
"Russia has become a pariah to the G7 because of their invasion. China wants no part of that," Bremmer wrote on Twitter, referring to the Group of Seven leading industrialized nations.
White House spokesman John Kirby said China should reject Russia's invasion: "The whole world should be lined up against what Mr Putin is doing," Kirby told CNN.
Russian Foreign Minister Sergei Lavrov later told reporters the talks with China had been excellent.
The last time Putin and Xi met they signed a "no limits" friendship agreement between their countries. Three weeks later, Russia invaded Ukraine in what it called a "special military operation" to "disarm" its smaller neighbour. Ukraine and the West accuse Russia of an unprovoked war of aggression.
Ukraine has accused Russian forces of targeting civilians and of war crimes, which Moscow denies. The day after he made a surprise visit to the recaptured northeastern town of Izium, President Volodymyr Zelenskiy said Ukrainian authorities found a mass grave there. He said more information should be made available on Friday.
Pope Francis on Thursday said it was morally legitimate for nations to supply weapons to Ukraine to help the country defend itself from Russian aggression.
"This is a political decision which it can be moral, morally acceptable, if it is done under conditions of morality," Francis said in an airborne news conference while travelling from a trip to Kazakhstan.
Francis also urged the Kyiv government to be open to eventual dialogue, even though it may "smell" because it would be difficult for the Ukrainian side.
In Washington, U.S. officials said the United States will soon announce a new $600 million weapons package for Ukraine's military.
Also on Thursday, Germany said it would supply two more multiple rocket launchers to Ukraine and European Commission President Ursula von der Leyen said Europe should support Ukraine with battle tanks as Ukrainians were proving they can defend themselves if they have the right military equipment.
Russian Foreign Ministry spokeswoman Maria Zakharova said any decision by the United States to supply Ukraine with longer-range missiles for U.S.-made HIMARS system would cross a "red line" and make the United States "a direct party to the conflict".
In Kyiv, von der Leyen held talks with Zelenskiy where she told him Ukraine's accession process to the European Union was well on track.
"It's impressive to see the speed, the determination, the preciseness with which you are progressing," she said.
Ukraine became a candidate to join the EU in June.
Von der Leyen said "you have your European friends by your side as long as it takes."
After a week of rapid Ukrainian gains, Ukrainian officials said Russian forces were fortifying defences and it would be hard to maintain the pace of the advance.
Putin has yet to comment publicly on the setback suffered by his forces in northeastern Ukraine this month. Ukrainian officials say 9,000 sq km (3,400 sq miles) has been retaken, territory about the size of the island of Cyprus. Russian troops have abandoned dozens of tanks and other armoured vehicles in haste.
Footage shot by Reuters on Thursday in the eastern town of Kupiansk, which Ukrainian forces recaptured last week, showed many buildings had been damaged or burned out.
"No electricity, no communications ... if there were communications we could least talk to family. If only there hadn't been all this bombing with everyone in their basements," said one man.
The speed of the advance has lifted hopes of further gains before the winter sets in.
But Serhiy Gaidai, governor of Ukraine's eastern Luhansk region, said it would still be a tough fight to wrest control of his region back from Russia, which recognises it as an independent state controlled by separatists.
There was no let-up either in Russia's daily missile strikes, a day after it fired cruise missiles at a reservoir dam near Kryvyi Rih, Zelenskiy's hometown in central Ukraine.
Authorities in Kryvyi Rih are working to repair the damage and as a result water levels are receding, said Kyrylo Tymoshenko, deputy head of the presidential administration.
Ukrainian forces repelled three Russian attacks north of the city of Donetsk on Thursday, the armed forces' general staff said in a Facebook post.
Russian forces had launched attacks on several settlements on the Kharkiv frontline in the past 24 hours, the General Staff of Ukraine's Armed Forces said.
Reuters was not able to verify battlefield reports.
Maps: Ukraine’s swift counteroffensive https://graphics.reuters.com/UKRAINE-CRISIS/lbvgnkwerpq/ukrainianCounteroffensive.jpg
(Reporting by Reuters bureaux; Additional reporting by Anthony Deutsch; Writing by Andrew Osborn, Alexandra Hudson and Grant McCool; Editing by Peter Graff, Frank Jack Daniel, Andrew Heavens and Daniel Wallis)