Jaishankar said China, in violation of the 1993 and 1996 agreements not to mass troops on the Line of Actual Control, chose to do so, and added that its attempt was obviously to unilaterally change the LAC.
Indian and Chinese troops remained engaged in an eyeball-to-eyeball situation in several disputed areas.
People familiar with the situation in the region said the two sides were engaged in trying to resolve the dispute, but there was no indication of a positive outcome yet as both the armies continued to bolster their positions in disputed areas of Pangong Tso and Galwan Valley and Demchok.
When asked for an update on Tuesday's military-level talks, Chinese foreign ministry spokesperson Hua Chunying told a media briefing in Beijing that both sides reached progress for promoting further disengagement of the border troops at the Western Sector.
Over the last few weeks, bipartisan support for India against China has been increasing.
The Indian delegation at Thursday's talks is likely to be led by Naveen Srivastava, Joint Secretary (East Asia) in the external affairs ministry, they said.
Most of India's reserves for war in the mountains have been sucked in by the standoff with China. A large part of India's airpower has also similarly been committed on the eastern border. By moving these reserves to the China border, India has been weakened vis-a-vis Pakistan. All in all, the nightmare scenario for India of a two-front war may well come true, warns Colonel Anil A Athale (retd).
In March last year, a petition was filed in the Supreme Court by Rajat Sharma and Dr Neh Srivastava who demanded that a former Jammu and Kashmir chief minister be booked under the sedition law, claiming he had sought China's help to restore the erstwhile state's special status.
At least 20 Indian soldiers were killed in the violent face-off, government sources said and added that the casualty numbers could rise.
Gen Pande also said that Indian troops are adequately deployed along the Line of Actual Control to deal with any situation and that guidance has been given to them to "remain firm and resolute" in their tasks.
Defence Minister Rajnath Singh on Monday said that decision on Pakistan-occupied Kashmir (PoK) should have been taken during 1971 war between India and the neighbouring country.
External Affairs Minister S Jaishankar on Thursday conveyed to his Chinese counterpart Wang Yi the need for an early resolution of all outstanding issues along the Line of Actual Control in eastern Ladakh, and asserted that bilateral ties should be based on mutual respect, mutual sensitivity and mutual interest.
'The greater the delay, the more the likelihood of crucial evidence being destroyed.'
The talks till now have resulted in the resolution of issues in North and South Bank of Pangong Tso, Galwan and Gogra Hot Spring areas.
Yes, we (Quad) had a discussion on India-China relations because it was part of how we briefed each other about what was happening in our neighbourhood, Jaishankar said.
The Chinese action followed 'India's recent, illegal construction of defence facilities across the border into Chinese territory in the Galwan Valley region', a write-up in the state-run Global Times tabloid said, quoting unnamed military sources.
His comments came in the midst of India's bitter border row with China along the LAC in eastern Ladakh.
The NSA particularly highlighted the need for resolving outstanding issues as quickly as possible and talked about the need for maturity and sincerity in dealing with the issue.
The chief of air staff said Chinese actions along the frontier including in the Ladakh sector are being monitored constantly and the IAF's overall preparations are part of continuing efforts irrespective of challenges from China.
The ministry of external affairs said both sides suffered casualties that could have been avoided had the agreement arrived at earlier at the higher level been scrupulously followed by the Chinese side.
'China is unwilling to restore the status quo ante of April 2020.' 'India will have to weigh its options based on this premise.'
'(The) PM has surrendered Indian territory to Chinese aggression. If the land was Chinese: Why were our soldiers killed? Where were they killed,' he asked on Twitter, tagging the prime minister's remark.
'Today, our vast green pastures where local herders used to take their cattle to graze have been taken over by the Chinese.' 'The people in the Galwan Valley have lost their lands where their cattle used to graze.'
In an interactive session at a think-tank in Paris, Jaishankar said he was optimistic about resolving the issue through dialogue and that significant headway has been made in many of the friction points.
The talks between the two armies are going to be held this week at multiple locations including Patroling point 14 (Galwan area), Patrolling point 15, and Hot Springs area, top government sources said.
India's top military and strategic brass on Tuesday reviewed the overall situation in eastern Ladakh amid indications that the latest round of talks between senior military commanders of Indian and Chinese armies on the next phase of disengagement of troops may not have produced encouraging results, people familiar with the developments said.
Senior commanders of the two armies held intense negotiations for nearly 11 hours on Sunday at a designated meeting point in Moldo on the Chinese side of the Line of Actual Control.
Gen Naravane said a "befitting response" was given to the "conspiracy" to make unilateral changes on the border and that the sacrifice of the Galwan heroes in eastern Ladakh will not go waste.
'Anyone familiar with Modi's track record will know he never forgets a slight, a betrayal,' notes Virendra Kapoor.
The intrusions into India were likely carried out by the PLA's better trained and equipped 'mobile operational units'.
China has protested to India over Chief of Defence Staff General Bipin Rawat's reported remarks about Beijing constituting the "biggest security threat", the Ministry of Defence here said on Thursday.
As tension escalated at the Line of Actual Control (LAC), the sources said around 50-60 soldiers of Chinese People's Liberation Army (PLA) approached the Indian post in the southern bank of Pangon lake area at around 6 pm but the Indian Army personnel posted there strongly confronted them, forcing their retreat.
The annual threat assessment of the US Intelligence Community released by the Office of Director of National Intelligence (ODNI) also said that the 'expanded military posture by both India and China along the disputed border elevates the risk of armed confrontation between two nuclear powers that might involve direct threats to US persons and interests and calls for US intervention'.
'If the situation escalates, then mini-scale firing might happen.'
Rezang La is the site of an epic battle where Indian troops bravely fought the Chinese soldiers in 1962.
The US actions can be seen as a riposte to India's neutral position on the Ukraine crisis, its continuing import of Russian arms and oil thus undermining Western sanctions, argues Colonel Anil A Athale (retd).
'In South Asia, unlike Southeast, East, or Central Asia, there is a natural hegemon: India. China cannot cast it aside easily'
'Even if there is no full-scale war, Galwan-like skirmishes cannot be ruled out.'
China and India have agreed to work to maintain peace along the Line of Actual Control and resolve the border standoff through talks while implementing the consensus reached between the two countries' leadership that 'differences' do not escalate into 'disputes', a top Chinese official said.
The army made the comments as part of a statement trashing a media report that said the Chinese military has again crossed the Line of Actual Control in eastern Ladakh at several places and that there has been at least one incident of clash between the two sides.