WASHINGTON: Prime Minister Narendra Modi today laid a wreath at the Tomb of Unknown Soldiers and paid homage to Indian-American astronaut (late) Kalpana Chawla at the Arlington National Cemetery in Washington.

“Honouring sacrifice, saluting valour. Formal engagements begin with a solemn ceremony,” External Affairs Ministry spokesperson Vikas Swarup tweeted.

“In homage to heroism and indomitable courage,” Mr Swarup said in another tweet.

He also had a brief interaction with Kalpana Chawla’s husband and family members, senior officials from NASA, Indian-American astronaut Sunita Williams and her father at Space Shuttle Columbia Memorial.

US Defense Secretary Ashton Carter accompanied the Prime Minister. Indian Ambassador to the United States Arun K Singh, Foreign Secretary S Jaishankar, US Ambassador to India Richard Verma and Assistant Secretary of State for South and Central Asia Nisha Desai Biswal were also present on the occasion.

In homage to heroism and indomitable courage. PM @narendramodi at the Space Shuttle Columbia Memorial pic.twitter.com/HXJwgPFs8f

— Vikas Swarup (@MEAIndia) June 6, 2016

“All of us are very honored that he took time to come and acknowledge the shuttle catastrophe and the deep cooperation that we have with India in space,” Ms Williams told news agency PTI after her brief interaction with Prime Minister Modi.

“Personally it is commemorating my friend (Kalpana Chawala),” Ms Williams said.

PM Modi spoke with Sunita’s father in Gujarati and invited them to visit India. “With health permitting, I definitely look forward to visiting India,” her father said.

Kalpana Chawla’s husband Jean-Pierre Harrison presented a set of books on the late astronaut, including a biography written by him, to the Prime Minister.

The Tomb of the Unknowns is a monument dedicated to American service members who have died without their remains being identified.