India is a strategic partner with whom the US engages in a "full and frank" dialogue, and US President Donald Trump has been very clear with New Delhi on his concerns over its purchase of Russian oil and trade imbalance with Washington, a US State Department official said, reported news agency PTI.

"What I can say in terms of India is that the President has been very clear in terms of the concerns he has regarding the trade imbalance, regarding the concerns he has when it comes to the purchase of Russian oil. You have seen him take action directly on that," State Department Principal Deputy Spokesperson Tommy Pigott said at a press briefing on Thursday, reported PTI.

He was responding to a question on Prime Minister Narendra Modi's visit to China for the Shanghai Cooperation Organisation summit from August 31 to September 1, his first visit to the country in seven years.