President Donald Trump said the United States may sharply increase tariffs on India if New Delhi fails to scale back its purchases of Russian oil, adding fresh pressure as trade negotiations between the two countries remain stalled.

Speaking to reporters aboard Air Force One on Sunday, Trump said he had made his displeasure clear to Indian Prime Minister Narendra Modi over India’s energy ties with Moscow.

“Modi is a good guy. He knew I was not happy, and it was important to make me happy,” Trump said.

Asked directly about India’s continued imports of Russian crude, Trump warned that Washington could move quickly on trade penalties.

“They do trade, and we can raise tariffs on them very quickly,” he said.

India’s commerce ministry did not immediately respond to requests for comment.

The remarks follow months of negotiations after the United States last year doubled tariffs on Indian goods to 50 percent, citing India’s purchases of discounted Russian oil. The tougher stance unsettled investors, with Indian technology stocks sliding on Monday amid concerns that strained relations could further delay a U.S.–India trade deal.

Republican Senator Lindsey Graham, a close Trump ally traveling with the president, said U.S. sanctions on Russian energy firms combined with higher tariffs had already pushed India to reduce imports from Russia. Graham is backing legislation that would allow tariffs of up to 500 percent on countries that continue buying Russian crude.

“If you are buying cheap Russian oil, you keep Putin’s war machine going,” Graham said, adding that tariffs are meant to force countries to make “a hard choice.”

According to Graham, Trump’s pressure is the main reason India is now buying “substantially less Russian oil.”

Trade analysts warn India’s cautious approach may be weakening its negotiating position. Ajay Srivastava, founder of the Global Trade Research Initiative, said Indian exports already face a 50 percent U.S. tariff, with roughly half linked to Russian oil purchases.

“Ambiguity no longer works,” Srivastava said, urging New Delhi to clearly define its stance. He warned that even a full halt to Russian oil imports may not end U.S. pressure, which could shift to other trade demands, while higher tariffs risk deeper export losses.

India has asked refiners to provide weekly disclosures of Russian and U.S. oil purchases as it seeks to address U.S. concerns. Prime Minister Modi has spoken with Trump at least three times since the tariffs were imposed, but talks remain unresolved.