The EU is looking to "choke off" revenue Russia uses for its war on Ukraine by slapping "prohibitive tariffs" on grain and related imports into the bloc, its trade commissioner said Friday.

The proposal from the European Commission was being put to European Union leaders holding a summit in Brussels on Friday.

The added sanctions, welcomed by Kyiv, will not apply to Russian grain transiting through the European Union to other markets, so as not to disrupt food supplies elsewhere, trade commissioner, Valdis Dombrovskis, said.

Ukrainian President Volodymyr Zelensky had complained to the EU leaders on Thursday, via video link, that it was not fair Russian grain continued to have "unrestricted" access to their markets, while Ukrainian imports were being limited.

Brussels has been seeking to increase pressure on Russia's finances after several rounds of sanctions that have already frozen Russian assets in the 27-nation bloc, targeted Russian leaders including President Vladimir Putin, and curbed trade.

At the same time, the commission has been multiplying concessions to Europe's farmers, who have been holding protests over depressed income, part of which they blame on grain imports from war-torn Ukraine.

Commission president Ursula von der Leyen said late on Thursday that the proposed tariffs would "prevent Russian grain from destabilising the EU market in these products".

- Global food security -

Dombrovskis, speaking on Friday, said: "Today's proposal is a timely and necessary step."

The tariffs were also to be imposed on products from Belarus, which served as a staging ground for Russia's all-out invasion of Ukraine.

The proposal follows an increase in Russian agricultural imports into the EU in 2023, according to the commission.

The tariffs would make imports "commercially unviable" and "help put a stop to the Russian practice of illegally exporting stolen Ukrainian grain into the EU", Dombrovskis said.

"We have been careful to uphold global food security. This measure will not affect the transit of Russian and Belarussian grain products to third countries."

Under World Trade Organization rules, virtually all Russian grain has until now been exempt from EU import duties.

Despite sanctions taking aim at huge swathes of Russia's economy, the EU until now avoided targeting the farm or fertiliser sectors -- for fear of destabilising the global cereal market and undermining food security in Asia and Africa.