Nepal's lower house cleared a constitutional amendment bill to give legal backing to a map showing areas such as Lipulekh as Nepalese territory, prompting India to claim that such "artificial enlargement of claims" violates an understanding to resolve boundary issues through dialogue or discussion.
The map depicts Lipulekh, Kalapani and Limpiyadhura as part of Nepal.
The bill was supported by all the 258 lawmakers present and voting.
The clearance of the bill came on the day when hundreds of protesters hit the streets of the country's capital Kathmandu over the government's handling of the COVID-19 pandemic.
In response to the development on Saturday, India's external affairs ministry spokesperson Anurag Srivastava said: " 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".
"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 added.
At the four-hour-long discussion in the House of Representatives, Nepal's Prime Minister KP Sharma Oli was asked by lawmakers to take steps to reclaim control of Lipulekh, Kalapani and Limpiyadhura from India.
Some from the Communist Party of Nepal preferred continuing with border restrictions on the movement of people that were introduced due to COVID-19.
The Oli government has repeatedly said that Nepal would "get back the land occupied by India" through dialogue and has also asked India to convene a foreign secretary-level meeting to discuss the boundary row.
Hours before the lower house of Nepal's Parliament voted on the amendment, Indian Army chief Gen MM Naravane said: "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".
Nepalese officials claim that atleast three proposals to India for talks since last November were ignored, with the most recent one in May. Nepal's Prime Minister KP Sharma Oli has said that Lipulekh, Kalapani and Limpiyadhura are part of his country's territory on the basis of the Treaty of Sugauli signed with the British in 1816, which mentions that all areas east of the Kali river belong to Nepal.
The India-Nepal border conflict comes at a time when India is engaged in a tense stand-off with Chinese troops in several sections of the Line of Actual Control (LAC).