PM Modi had invited Donald Trump for a visit to India during their talks in Washington in June, 2017.
US Ambassador to India Kenneth Juster on Thursday said President Donald Trump's inability to participate as the chief guest at India's Republic Day celebrations next year was a "purely scheduling issue".
Mr Trump has declined India's invitation to be the chief guest at the parade citing pressing engagements, including his State of The Union (SOTU) address, around the time India will celebrate its Republic Day on January 26.
Asked if Mr Trump declining India's invitation had something to do with India signing a deal with Russia on S-400 missile defence systems, Juster, speaking to reporters on the sidelines of an event here, said, "No, that is a purely scheduling issue."
Earlier this week, a White House spokesperson, when asked about Mr Trump's decision, had said, "President Trump was honoured by Prime Minister Modi's invitation to him to be the chief guest of India's Republic Day on January 26, 2019, but is unable to participate due to scheduling constraints."
Prime Minister Narendra Modi had invited Mr Trump for a visit to India during their talks in Washington in June, 2017.
Every year, India invites world leaders to attend its Republic Day celebrations.
In 2015, the then US president Barack Obama had attended it as the chief guest, which was his second visit to India as the American president.
On whether India will get a waiver from the US on Chabahar amid sanctions on Iran, Mr Juster said, "These are matters that our two governments are discussing and we are working together on that."