Russia is unable to honour its arms delivery commitments to India because of the war in Ukraine, the Indian Air Force (IAF) said, placing a potential strain on New Delhi's relationship with its largest defence supplier as Moscow attempts to ramp up weapons production.
An IAF representative told an Indian parliamentary committee that due to the Ukraine war a "major delivery" from Moscow "is not going to take place."
The admission, published in a report by India's lower house of parliament on Tuesday, is the first official confirmation by Indian authorities amid swirling rumours and reports in local media suggesting shortcomings in Russian capacity.
"They have given us in writing that they are not able to deliver it," the representative said, according to the report.
CNN has contacted the Russian Embassy in New Delhi but did not receive a response at the time of publishing.
The report did not mention the specifics of the delivery.
The biggest ongoing delivery is the S-400 Triumf air defence system units India bought in 2018 for $5.4 billion. Three of these systems have been delivered and two more are awaited, Reuters reported.
IAF also depends on Russia for spares for its Su-30MKI and MiG-29 fighter jets, the mainstay of the service branch, according to Reuters.
Russia is the world's second-largest arms exporter, according to the Stockholm International Peace Research Institute (SIPRI).
Earlier this month, Russian President Vladimir Putin announced a large-scale effort to build up capacity to produce more weapons for the war in a move he said was "urgently needed."
Putin's order also followed repeated complaints by Wagner chief Yevgeny Prigozhin that his mercenaries were not receiving sufficient munitions in their prolonged battle for the eastern city of Bakhmut.
New Delhi has strong ties with Moscow dating back to the Cold War, and remains heavily dependent on the Kremlin for its military equipment -- a vital link given the ongoing tensions along India's shared Himalayan border with an increasingly assertive China.
The admission by the IAF is "very serious," according to Harsh V. Pant, vice president of studies and foreign policy at the New Delhi-based think thank Observer Research Foundation.
"I think it underscores the problems that (India) has been bedevilling this relationship for quite some time," he added. "And the Ukraine crisis has accelerated the trend that India, for a very long time, has been trying to diversify, and was concerned about its over-dependence on Russia."
A SIPRI report published this month said Russia remains India's largest arms supplier, despite a drop in defence imports from 62% to 45% between 2017 and 2022.
Experts have suggested the drop could be because India is looking to diversify its imports and push more home-grown equipment.
Last September, a US State Department official said Washington was in "deep" talks with India over its reliance on Russian arms and energy.
Russia "is no longer a reliable weapons supplier" and Indian representatives are "coming to understand that there could be real benefits for them (in finding other markets)," the official told reporters in New York.
Since the start of the war in Ukraine, India, the world's largest democracy, has carefully navigated a middle path.
New Delhi has refused to condemn Moscow's brutal assault in various United Nations resolutions. And rather than cutting economic ties with the Kremlin, India has undermined Western sanctions by increasing its purchases of Russian oil, coal and fertilizer.
India has also maintained close ties to the West -- particularly the United States -- as it works to thwart China's rise.
As Putin continues his aggression, driving food and fuel prices to soar, experts have suggested Moscow's actions in Ukraine could be testing New Delhi's patience.
And the Indian Air Force going public about Russia's arms delivery failure could be a sign of that strain, said Pant, from the Observer Research Foundation.
"I think the relationship (between India and Russia) has been under stress for a long time," he said. "It's now becoming clear that the present trajectory of this relationship is becoming increasingly unsustainable (because of) what is happening in Ukraine."