Trump in his speech said that border security is vital to America as well as India and "India and the US will together fight radical Islamic terrorism".
The little reference became a trending topic on Twitter within no time.
"Radical Islamic Terrorism comes in Trump's speech. Liberals must be fuming," tweeted one user.
"Radical Islamic Terrorism... very strong words from @POTUS Thanks Mr. President... we all love you," posted another.
Another user posted: "He really meant it. A direct message to Pakistan and other countries which fund terrorism."
Trump said that "we honour all the brave American and Indian military service members who work together to safeguard our freedom."
"We are committed to protecting innocent civil from the threat of radical Islamic terrorism," he told the packed NRG arena.
One Twitter user posted: "Trump goes direct on radical Islamic terrorism and securing our borders and illegal immigration, with a standing ovation from the crowd."
"The best part of @realDonaldTrump is he does not mince words radical Islamic terrorism, illegal immigrants & border security are Paramount, no sugar coating take it or leave it," wrote another.
"A brutal and direct jibe by #Trump at a few countries. From the last few years, people had started saying 'Terrorism has no religion.' Now, we are back to reality," said a user.
( With inputs from IANS )