NEW DELHI: Common concerns over challenges and threats emanating from China including in the Indo-Pacific region are expected to result in an expansion of overall strategic and defence cooperation between India and the US under Joe Biden's presidency, former diplomats and security experts said. With Biden's focus on policy priorities after his historic inauguration as the 46th American President on Wednesday, his nominee for Secretary of State, Antony Blinken, gave a clear signal about the new administration's approach towards Asia when he said the US would stay tough on China as it poses the "most significant challenge" to the country while describing India as a bipartisan success story.

Former diplomat Arun Singh, who served as Indian envoy to the US during 2015-16, said the challenges being faced by India from China and the threat Washington sees from the economic, technological and military rise of the communist nation will certainly provide some space for the two countries to "do more together".

"With the convergence of interests between the two countries in different areas, especially in the Indo-Pacific, I would expect the cooperation only to get strengthened," Singh told .

Ambassador Rajiv Bhatia, a distinguished fellow at leading think-tank Gateway House, said the trend of forward movement in overall ties witnessed in the last 20 years is expected to continue.

"But we will have to watch how America's Asia Policy and China policy actually evolve in the coming months because there is a lot of uncertainty about these two particular policies and their interplay will actually impact India-US ties. So let us wait and watch," the former diplomat said.

Bhatia said the strategic cooperation between the two nations is bound to expand in the Indo-Pacific, a region that has been witnessing increasing Chinese military assertiveness in the last few years.

"It is a classic case where the US needs India, having already declared that China is their principal rival, and India also certainly needs the US given the current geopolitical situation in Asia. I think we certainly can expect defence and security cooperation (between India and the US) to go up," he said.

During a Senate confirmation hearing, Blinken said that there was no doubt that China poses the "most significant challenge" of any nation state to the US.

Noted strategic affairs expert G Parthasarthi said Biden's policies reflect concerns over China's aggressive behaviour against many countries in Asia in recent years, and both India and the US will have to act in their own interests.

"A number of Asian countries are facing pressure from China. This is a strange phenomenon in the Xi Jinping era...The fact is that neither India nor the US, in my view, want a tense relationship with China but they have to act in their own interests," he said.

Former Deputy Chief of Army Staff Lt Gen Subrata Saha (Retd) said the broad direction of the strategic ties between the two countries will remain the same and their cooperation will witness further momentum.

Asked about the possibility of the US imposing sanctions on India under the Countering America's Adversaries Through Sanctions Act (CAATSA) for the purchase of S-400 missile defences from Russia, Saha said top US officials have been taking a "pragmatic view" on the issue.

"You cannot wish away overnight the fact that we have this huge dependency on Russia. So whether you put CAATSA or you don't put, if we have to bring our capability to the fore, we have to have all channels open. Ultimately India will take decisions based on its own strategic interests," he said.

"To expect that India will start compromising its strategic necessities because of another government's policy, I do not think it is a reasonable assumption or fair expectation," he said.

The US imposed sanctions on Turkey recently under the CAATSA for the purchase of S-400 missile defences from Russia.

Singh hoped that India and the US would be able to find a way to have some kind of a limited trade agreement and then build further on that.

At the same time, he said, the US has had difficulty in its trade relations with not just India but also other countries including its partners in Europe.

"It has had issues at times with Japan and with Canada," he said.

India and the US under the Trump administration held multiple rounds of negotiations for a trade deal, but it did not fructify.

Former US ambassador Kenneth Juster, who is leaving India on completion of his tenure, had referred to "frictions and frustrations" on trade and investment ties between India and the US and said the two countries were even unable to finalise a "small trade package" despite persistent efforts.

Singh said that the defence and security cooperation between India and the US is bound to expand.

"The Obama administration had declared India as its major defence partner. They had also started the defence trade and technology initiative. The Trump administration took it further by putting India in the Strategic Trade Authorisation level one category which is meant for closest allies," he said.

"Therefore, given that one can expect that in defence and technology the trend would continue," he added.

Singh said the two sides should focus on cooperation in areas like artificial intelligence, quantum computing and big-data analysis.

"It will be better for the two to explore new opportunities for cooperation in these areas rather than just getting bogged down in existing levels of production and trade," he said.