Ukrainian President Petro Poroshenko lashed out at India on Friday over a visit by the leader of Crimea, the former Ukrainian territory annexed by Russia, who accompanied President Vladimir Putin's annual summit delegation this week.
India does not back Western sanctions against Russia, and the unofficial trip by Sergey Aksyonov could spoil the mood before Prime Minister Narendra Modi hosts US President Barack Obama for India's Republic Day festivities in January.
Poroshenko, addressing the Lowy Institute think tank in Sydney, said India was placing more importance on "money" than "values" by welcoming Aksyanov, and it was not standing with "civilisation" against Russian aggression.
"It is not an easy job, to keep the world together," Poroshenko said to laughter, when asked by a journalist about the visit.
"The Indian position doesn't help, it doesn't save Mr Aksyanov," he added. "He is a criminal, it's very simple. He has a criminal background and no doubt he has a criminal future."
State Department spokeswoman Jen Psaki said the United States was "troubled" by reports that Aksyonov may have been part of Putin's delegation and was seeking more information.
"We understand that the Indian Ministry of External Affairs have said they were not officially aware of his visit or his participation in the delegation ... We are seeking further clarification on that."
Psaki also referred to reports of new nuclear and defence deals between India and Russia and reiterated Washington's view that it was "not time for business as usual with Russia".
Aksyonov arrived at the upscale Oberoi hotel in New Delhi accompanied by Russian diplomats to be greeted by Gul Kripalani, a Mumbai-based seafood merchant who wants to boost trade with Russia.
Speaking to reporters after signing a memorandum of understanding to promote business, Aksyonov said his visit had "a private character" and he did not take part in any official events.
He tweeted separately, however, that he had come to India as "a member of the delegation under the leadership of the president of the Russian federation, Vladimir Putin".
The towering 42-year-old, previously an obscure nationalist politician, was elected in a closed session of the regional parliament after Russian forces in February took control of the Crimean peninsula in a bloodless operation.
He masterminded a quickfire referendum to join Russia that was recognised by Moscow. Kiev and the West say it was rigged.
It was clear that his visit enjoyed Russia's full diplomatic backing, with the consul general to Mumbai and an aide to Ambassador Alexander Kadakin attending.
No Indian officials were present.
News of the event leaked out on Wednesday when the Russian embassy invited reporters to a signing ceremony only to cancel late in the evening.
A spokesman for India's Ministry of External Affairs said he was not officially aware of the Crimean visit. It is highly unlikely that such an event would have taken place without New Delhi being in the loop, however.
At a joint news conference after meeting Putin, Modi emphasised India's deep security ties with Russia. Moscow was long India's top arms supplier until the United States, which is keen to forge closer ties with New Delhi, took top spot recently.
"Even if India's options have increased, Russia remains our most important defence partner," Modi told reporters. No potentially
awkward questions were allowed at the tightly stage-managed event.
India, which observes a policy of non-intervention, has refrained from criticising Moscow's takeover of Crimea and support for an uprising in eastern Ukraine that has killed more than 4,300 people since April.