Here are the countries most exposed to that ultimatum, if he follows through:

- China -

China is by far Russia's biggest trading partner, with annual import and export flows between the two totalling nearly $240 billion according to the Bruegel think tank.

That Brussels-based institute has been piecing together monthly trade figures for Russia since that country in April 2022 ceased publishing detailed figures as it came under sanctions for its all-out invasion of Ukraine.

China accounts for 48 percent of Russia's trade flows, according to Bruegel.

In the year to May 2025, Russia exported $125 billion in goods including natural gas and oil, medical equipment and chemical products.

Its imports from China amounted to $113 billion, mainly steel, equipment, electronics and textiles.

Chinese foreign ministry spokesman Lin Jian, responding to Trump's threat on Tuesday, said his country's position on Ukraine had always been "clear and consistent -- we have always believed that dialogue and negotiation are the only viable solution to the Ukraine crisis".

China "firmly opposes all illegal unilateral sanctions and long-arm jurisdiction", he said, adding: "There are no winners in a tariff war."

- India -

India is Russia's third-biggest trade partner, with exchanges totalling $68 billion in the year to May, according to Bruegel.

Russian exports to India -- primarily fossil fuels -- accounts for 90 percent of that. India is the biggest buyer of Russian oil in the world.

India's exports to Russia are essentially nuclear reactors, machinery and pharmaceutical compounds.

Yet clandestine exchanges are believed to greatly expand trade, according to several media reports. The Wall Street Journal, for example, has said that Indian shipping companies deploy a shadow fleet to transport sanctioned Russian oil.

- Belarus -

Belarus, a close ally of Russia's and itself under US and EU sanctions for helping Moscow in its war on Ukraine, relies heavily on Russian oil and gas for its energy needs.

Trade between the two amounted to $60 billion between January and October 2024, according to Russian customs figures.

But Belarus's exposure to the threatened US tariffs could be limited, given it exports just $21 million worth of goods to the United States, principally food products, according to the UN Commodity Trade Statistics Database.

- EU and Turkey -

Even though the European Union has slapped several rounds of sanctions on Russia, it remains a big buyer of Russian gas.

According to Bruegel, the EU is likely Russia's second-biggest trading partner, with exchanges totalling $71 billion in the year to May, or 14 percent of Russia's total inflows and outflows.

The European Commission is seeking to reduce that trade, and has presented how it plans to phase out Russian natural gas imports by the end of 2027.

Turkey, not part of the EU, is Russia's fourth-biggest trading partner, according to Bruegel, which tallied $52 billion worth of exchanges last year.

Turkey largely imported Russian fossil fuels and exported electronics.

burx-lem/rmb/giv