Kathmandu/New Delhi: In a snub to India, Nepal's Parliament on Saturday unanimously voted to amend the Constitution to update the country's new political map, laying claim over three strategically key areas along the border with it.

In a show of unprecedented national unity, Opposition parties including the Nepali Congress, Rastriya Janata Party-Nepal and Rastriya Prajatantra Party voted in favour of the bill to amend Schedule 3 of the Constitution to update the national emblem by incorporating the controversial map featuring new areas of Lipulekh, Kalapani and Limpiyadhura along Nepal's border with India.

Reacting to Kathmandu's move, India termed 'Nepal's decision to update its new political map featuring areas which New Delhi maintains belong to it' as 'untenable'.

"We have noted that the House of Representatives of Nepal has passed a constitution amendment bill for changing the map of Nepal to include parts of Indian territory. We have already made our position clear on this matter," Ministry of External Affairs Spokesperson Anurag Srivastava said.

"This artificial enlargement of claims is not based on historical fact or evidence and is not tenable. It is also violative of our current understanding to hold talks on outstanding boundary issues," he said.

Earlier in the day, Indian Army chief Gen M M Naravane said bilateral ties with Nepal has always been strong and will remain so in the future.

"We have a very strong relationship with Nepal. We have geographical, cultural, historical, religious linkages. We have very strong people-to-people connect. Our relation with them has always been strong and will remain strong in the future," Gen Naravane told reporters in Dehradun.

In the midst of the border row, Gen Naravane had said that there were reasons to believe that Nepal objected to the road at the behest of "someone else", in an apparent reference to a possible role by China in the matter. The comments triggered an angry reaction from Nepal.

As soon as Nepal's Parliament meeting started, lawmakers from different political parties, donning face masks, took part in the deliberations.

Of the total 275 lawmakers in the lower house, all 258 lawmakers present in the house voted in favour of the Constitution amendment bill.

"The amendment proposal has been passed with more than two-thirds majority," announced Speaker Agni Sapkota.

The endorsement will now pave way for the government to expedite the process to replace the political map in Nepal's national emblem.

"This is a historic occasion, when the land we lost during the period of monarchy is being returned under the republican system. Nepal doesn't want to allow enmity to emerge with our southern neighbour from this issue," said former premier and president of ruling NCP Pushpa Kamal Dahal 'Prachanda'.

"I am confident that the long standing issue relating to land encroachment will be resolved once and for all through dialogue and diplomatic efforts," he said.

Expressing his party's support to the bill, Nepali Congress President Sher Bahadur Deuba said that Nepali people have stood united on the issue of nationality and territorial integrity. As per the Sugauli Treaty of 1816, the land east of Mahakali river belongs to Nepal, he said.

Speaker Sapkota rejected an amendment proposal submitted by Sarita Giri of Janata Samajwadi Party, saying that her proposal was not in line with Clause 112 (B) of HoR Regulations.

Giri sought to register an amendment proposal on the bill stating that Nepal did not have any evidence to claim the areas including Kalapani as her own sovereign territories. Following the rejection, Giri boycotted the session halfway.

The government had registered the bill in Parliament on May 22 and was presented it before the House on May 24.

On June 9, the Parliament unanimously endorsed a proposal to consider the Constitution amendment bill.

Now, the bill will be sent to the National Assembly where it will undergo a similar process. The ruling Nepal Communist Party commands two-thirds majority in the National Assembly (NA).

The NA will give lawmakers 72 hours to move amendments against the bill's provisions, if any.

After the NA passes the bill, it will be submitted to the President for authentication, after which it will be incorporated in the Constitution. After that, the new map will be used in all official documents, including the coat of arms.

The Cabinet had endorsed the new political map on May 18.

The bilateral ties came under strain after Defence Minister Rajnath Singh inaugurated a 80-km-long strategically crucial road connecting the Lipulekh pass with Dharchula in Uttarakhand on May 8.

Nepal reacted sharply to the inauguration of the road claiming that it passed through Nepalese territory. India rejected the claim asserting that the road lies completely within its territory.

Nepal last month released the revised political and administrative map of the country laying claim over the strategically key areas, more than seven months after India published a new map in November 2019.

India then sternly asked Nepal not to resort to any "artificial enlargement" of territorial claims.

Prime Minister K P Sharma Oli has been asserting that Lipulekh, Kalapani and Limpiyadhura belong to Nepal and vowed to "reclaim" them from India.

Meanwhile, Nepal government has formed a nine-member team of experts to collect historical facts and evidence related to the three disputed areas as part of the country's territory, The Kathmandu Post reported.