China demanded on Thursday that Ukraine immediately remove more than a dozen Chinese companies from a list of firms designated as "international sponsors of war", saying it wanted Kyiv to "eliminate negative impacts".

The remarks came after Reuters reported that China's ambassador in Kyiv had told senior Ukrainian government officials last month that the inclusion of the companies on the list could hurt bilateral ties.

"China firmly opposes the inclusion of Chinese enterprises in the relevant list and demands that Ukraine immediately correct its mistakes and eliminate negative impacts," a Chinese foreign ministry spokesperson told Reuters after the report was published. It did not specify what those impacts may be.

Beijing has close ties with Moscow and has refrained from criticising Russia's invasion of Ukraine, but it has also said the sovereignty and territorial integrity of all countries must be respected. It has offered to help mediate in the war.

Ukraine has listed 48 companies globally, including 14 from China, as "international sponsors of war" whose business activities it says indirectly assist in or contribute to Russia's war efforts.

"The ambassador said that all this (the situation with the blacklist) could have a negative impact on our relations," said one of two senior Ukrainian sources who spoke to Reuters about the meeting.

The source added that China had not set any conditions for Ukraine, but simply expressed its view about the list.

The second source suggested Beijing could link the matter to Chinese purchases of Ukrainian grain.

Before Russia's full-scale invasion on Feb. 24, 2022, China was Ukraine's biggest trade partner and it remains an important consumer of Ukrainian grain, sunflower oil and iron ore.

The blacklist, which has no legal implications for the firms it includes, takes issue with what it describes as extensive cooperation between Chinese and Russian companies in sectors including oil and gas, the main source of revenue for Moscow.

It features Chinese energy giants China National Petroleum Corporation (CNPC), China Petrochemical Corporation (Sinopec Group) and China National Offshore Oil Corporation (CNOOC).

Sinopec and CNOOC did not immediately respond to requests for comment. CNPC stated that the list was not a new development.

'REPUTATIONAL TOOL'

Ukraine's National Agency for Corruption Prevention describes the blacklist as a "powerful reputational tool for achieving the benevolence of elements of global supply chains (and) the exit of international business from Russia".

Though China is widely seen as an ally of the Kremlin, Ukraine has been careful not to anger the world's second largest economy throughout its war with Moscow, and it has repeatedly appealed to Beijing to join Kyiv's diplomatic efforts for peace.

Ukraine has been promoting its blueprint for peace at a series of high-level international meetings. China attended one of the meetings in Jeddah last year, but it has since refrained from attending.

China was the main destination for Ukrainian food exports shipped under a UN-brokered grain corridor established after Russia's invasion but now defunct. It accounted for around 7.9 million metric tons of the total 30 million tons transported via that route.

Under Kyiv's new Black Sea shipping corridor established last August, government data shows, some 30% of Ukraine's maritime exports, including food, metals and ore, were shipped to China.

With 14, China has the most companies on the blacklist, followed by the United States, France and Germany which have eight, four and four respectively.

China said on Tuesday that Chinese Vice Foreign Minister Sun Weidong met with Ukraine's ambassador to Beijing and exchanged views on issues of common concern, and that Sun had said the countries should respect and treat each other sincerely.