The United States and India share a historic bond as the world's oldest and largest democracies, US President Donald Trump said on Monday as he greeted India on its 77th Republic Day celebrations.

Trump's greetings came amid continuing strain in ties between the two countries over a range of issues, including Washington's policies on trade and tariffs. "On behalf of the people of the United States, I extend my heartfelt congratulations to the government and people of India as you celebrate your 77th Republic Day," the US president said.