US President Donald Trump's pressure on India to halt its oil imports from Russia and comply with sanctions on Iran has strained ties between Washington and New Delhi, who have enjoyed a healthy strategic partnership for decades.

With trade talks still stalled after several rounds of negotiations, Trump has imposed a 25% tariff on Indian exports to the US which took effect on August 1, and on Monday threatened to "substantially" increase it.

India has hit back, saying the tariffs are "unjustified and unreasonable" and that it would take "all necessary measures" to safeguard its "national interests and economic security." 

Deteriorating US-India relationship

After calling India a "friend" last week, Trump hardened his tone on Monday, saying New Delhi authorities "don't care how many people in Ukraine are being killed by the Russian War Machine" and are helping fund Russia's war effort in Ukraine through their purchases of Russian oil.

The tougher rhetoric is a marked shift in relations between India and the US.

Ties have deteriorated in recent months, despite the display of personal warmth and symbolic friendship when Prime Minister Narendra Modi met with President Trump earlier this year in Washington.

Commodore Uday Bhaskar, a security and strategic affairs expert, believes that despite Trump's "intimidatory" approach, India "does not seek a confrontation."

"However, the US has chosen to weaponize trade tariffs in a unilateral and abrasive manner. That is intimidation. And yes ... trust in Washington is low and the disappointment is high," Bhaskar told DW.

Amitabh Mattoo, dean of the School of International Studies at Delhi's Jawaharlal Nehru University, said that India will not be bullied by "tariffs, tantrums, or threats."

"Our ties with Russia and Iran reflect sovereign decisions, not defiance. We are not in the business of appeasement, nor of provocation. Strategic autonomy means engaging on our terms which is clear-eyed, confident, and calm. Let us not confuse noise for strategy," Mattoo told DW.

The downturn between Washington and New Delhi has coincided with Trump pursuing closer ties with India's neighbor, Pakistan.

The two nuclear-armed rivals recently fought a four-day conflict, which Trump said ended thanks to US mediation —  a claim Modi rejected.

The US and Pakistan signed a deal last month that will see Washington develop the South Asian nation's oil reserves in exchange for lower tariffs on its exports to the US.

Spotlight on India's Russia and Iran ties

India is now the biggest buyer of Russian crude oil by volume, according to data from Finland-based think tank the Centre for Research on Energy and Clean Air.

Approximately 35%-40% of Indian oil imports come from Russia, up from just 3% in 2021, the year before Russia launched its full-scale invasion of Ukraine.

While the West has looked to cut ties with Moscow, India has not joined Western sanctions against Russia.

Senior Indian officials and the Ministry of External Affairs have repeatedly stated that India's "steady and time-tested partnership" with Russia is not negotiable and will not be subject to outside pressure.

Trump has also justified the tariffs by pointing to India's ongoing trade with Iran, which has also been hit by Western sanctions over Tehran's nuclear ambitions.

Shanthie Mariet D'Souza, president of Mantraya, an independent research forum, said American policy "appears to be an expression of [Trump's] frustration to solve the Ukraine war and to pressure Iran."

"It also clashes directly with India's policy of strategic autonomy," she told DW.

D'Souza also cast doubt on whether Trump's aggressive approach will help resolve the situation, stressing that he risks alienating a willing and trustworthy partner in India.

Can diplomacy be the answer?

D'Souza said India will have to resort to diplomacy to navigate the crisis.

In the coming weeks, she said New Delhi will have to analyze whether continuing to buy cheap Russian crude oil is in line with its long-term strategic objectives.

"Over the past decade, India's strategic ties with the US have grown stronger, at the expense of its relations with Russia and Iran. Making a complete U-turn may no longer be a viable idea," D'Souza added.

Ajay Bisaria, a former diplomat who just returned from the US, said Trump is trying to reshape the world order by deploying two blunt instruments — tariffs and sanctions — with India facing the threat of both.

Despite the downturn and harsh rhetoric, Bisaria told DW that "India should play the long game, keep calm, and negotiate. The Trump phenomenon needs to be managed, not countered at every step."

India "must prioritize its national interest" with regard to Russian energy imports, Bisaria said, while also conveying to Washington that it "values its partnership" with the US — as long as the White House tones down its increasingly confrontational rhetoric and respects "India's red lines."

He pointed to an upcoming visit by a US delegation later this month as a target for a trade deal to be agreed.

"Trump should be cordially welcomed to sign the deal later in the year," Bisaria said.

Edited by: Karl Sexton