Over two terms in office, Prime Minister Narendra Modi has crafted his image as a strong nationalist leader with a muscular foreign policy.

Now amid India's biggest diplomatic and military dispute in recent years, Mr Modi is facing the challenge of managing domestic expectations of a strong response with the reality of facing off against a militarily superior neighbour.

India is grappling with the worst border trouble in decades with China in the Ladakh region following the death of 20 Indian soldiers in a violent clash in the Galwan Valley on Monday.

The deadly clash between the two sides went on for hours, leaving 76 other Indian soldiers injured. Some died when they fell off a high ridge amid sub-zero temperatures into the fast-flowing Galwan River.

Indian officials have accused the Chinese of using rods studded with nails as weapons, despite an agreement between the two sides forbidding the use of guns and explosives within 2km of the border.

Ten soldiers were released from Chinese custody on Thursday, according to the Indian military, while the casualties on the Chinese side are so far unknown.

While he acknowledged that China has not entered Indian territory, Mr Modi on Wednesday warned that the deaths "would not go in vain", and that India was capable of giving a befitting reply.

But he also indicated, just like China, that he did not want an escalation of the border tensions.

Analysts said Mr Modi has a tough time ahead of him, with coronavirus infections in the country still going up as well. India has now had 385,000 cases of Covid-19.

"This is undoubtedly the most challenging moment that Mr Modi has faced as prime minister because it comes as a double whammy with Covid-19. I think it is possibly the biggest challenge for any prime minister in several decades," political analyst Nilanjan Mukhopadhyay said.

He added: "Mr Modi is trapped between various options which are there before him (on China) and the public image he has created of being a strong leader. Will Modi live up to his muscular image? That will be something for which he will be looked at in history."

Within the military, hit hard by the deaths of 20 soldiers, there is still appetite for an additional armed response to push back Chinese troops from what India perceives to be its territory.

But the government, which will take the final call, has clearly indicated that the immediate priority is military and diplomatic talks.

Mr Modi, who won back-to-back elections, remains India's most popular politician even through the coronavirus pandemic.

He returned to power last year and has continued his dominance in Indian politics, tightening his grip on various institutions.

No opposition leader has been able to mount a credible challenge to the Prime Minister politically.

On foreign policy, however, Mr Modi's robust approach has largely been reserved for Pakistan, with which India also has border issues.

In 2019, India launched air strikes against what it said was a terror training camp in Pakistan, following a suicide bombing in which 40 Indian soldiers were killed.

While the facts of the strike were contested by Pakistan, the event helped the Modi government build up a domestic narrative of a tough foreign policy.

But the government can ill afford to follow the same template with China. Leaders of the ruling Bharatiya Janata Party have been careful in their remarks on China to the media and have refrained from fanning the flames of nationalism.

Still, domestic calls to boycott China are deepening.

"Clearly, public pressure will be there. What the government can do is no longer involve China (companies) in areas which are of strategic importance or government tenders, which will be showcased just to placate public opinion in the short term," said Professor Harsh V Pant, head of the strategic studies programme at the Observer Research Foundation.

India's media has reported that the government is looking at curtailing Chinese presence in telecommunications, for instance.

Mr Modi, who usually has a very fractious relationship with the opposition, has moved to arrive at some national consensus, holding a meeting yesterday with opposition leaders on the border row.

Opposition leaders were briefed by the defence and external affairs ministers on the developments at Galwan Valley.

Still, the opposition Congress has accused the government of not revealing the true depth of the issue. Congress president Sonia Gandhi is understood to have asked at the meeting for details of the violent clash on Monday and that the government should keep the opposition briefed.