Their remarks came amid the border face-off between India and China in eastern Ladakh.
Throwing their weight behind the India-US relationship which enjoys the bipartisan support, two top American lawmakers have said that close partnership between the two countries assumes significance in view of the "aggression" that New Delhi faces from Beijing.
Writing jointly to demonstrate the strong bipartisan support for the US-India relationship, the Chairman and Ranking Member of the House Committee on Foreign Affairs in a letter to External Affairs Minister S Jaishankar said members of both the parties recognise the impact that a strong US-India partnership will have on the trajectory of the 21st century.
"As Prime Minister (Narendra) Modi said in February of this year, our ties ''are no longer just another partnership. It is a far greater and closer relationship''", said the letter signed by Eliot Engel, Chairman of the House Foreign Affairs Committee and Michael T McCaul, its Ranking Member.
"This closer relationship is all the more important as India faces aggression from China along your shared border, which is part of the Chinese government's consistent pattern of unlawful and belligerent territorial aggression across the Indo-Pacific," the two powerful Congressmen said.
Their remarks came amid the border face-off between India and China in eastern Ladakh.
Twenty Indian army personnel were killed in the line of duty during the clashes with Chinese troops in eastern Ladakh's Galwan Valley on June 15. The Chinese side also suffered casualties in the clashes but it is yet to give out details.
The number of casualties on the Chinese side was 35, according to a US intelligence report.
The United States will remain steadfast in support of India's efforts to defend its sovereignty and territorial integrity, said the letter dated August 5 and was tweeted by the House Foreign Affairs Committee.
"As champions of the US-India relationship, we have been delighted to see our countries'' close cooperation on issues from defense to climate change. It is because of our support for the bilateral relationship that we note with concern that conditions in Jammu and Kashmir have not normalised one year after India''s repeal of Article 370 and the establishment of Jammu and Kashmir as a Union Territory," they wrote.
"We acknowledge the ongoing serious security and counterterrorism concerns in the region and look forward to working with your government to address these concerns while upholding our shared commitments to the democratic values and freedoms on which our countries'' bond was built," the lawmakers wrote.
"As Prime Minister Modi said earlier this year, ''Unity in diversity and unity''s vibrancy is the key to a strong relationship between India and America''. We look forward to working with you to continue to strengthen and advance this vibrant and consequential relationship," Engel and McCaul wrote.