US President Donald Trump assured Wednesday that Indian Prime Minister Narendra Modi promised him that New Delhi would stop buying Russian oil after imposing tariffs on India.

"I was unhappy with India buying oil [from Russia], and he assured me today that they will not buy oil from Russia," the Republican leader said in the Oval Office, in response to a question from the press.

"It's a big step forward. Now I need to convince China to do the same," he added.

The move, which has not been confirmed by the Indian government, would boost Trump's efforts to pressure Moscow to negotiate an end to the war in Ukraine.

According to Trump, this decision will not occur immediately, but"in a short space of time."

The Indian prime minister met on Saturday with the new US ambassador, Sergio Gor, a close aide of Donald Trump, just hours after his arrival in New Delhi.

On August 27, the US President imposed a 50% tariff on Indian exports in retaliation for New Delhi's purchases of Russian oil, which it believes is fueling Vladimir Putin's war in Ukraine.

The United States is India's largest trading partner.

The US president's comments come as he is set to meet with his Ukrainian counterpart, Volodymyr Zelensky, on Friday.

This will be the Ukrainian President's third visit to Washington since Donald Trump's return to power.

Ukraine is the target of new waves of Russian bombings against its energy infrastructure.

Trump said on Sunday he could threaten Vladimir Putin with sending long-range US Tomahawk missiles to Kyiv if Russia did not agree to end the war triggered by Russia's 2022 invasion of Ukraine.

When questioned today, Trump noted that the Ukrainian President wanted to"go on the offensive" and that he intended to "make a decision on the matter."