"Spoke to Ireland's new Taoiseach Leo Varadkar on phone to congratulate him and reaffirm our commitment for stronger India-Ireland ties," he tweeted.
Varadkar, Ireland's first Indian-origin premier, on Wednesday officially took over from Enda Kenny as Taoiseach, as the Irish prime ministerial title is known.
Varadkar is the youngest and the first openly gay prime minister of the Catholic-majority country.
His father Ashok, hails from Varad, a village in Sindhudurg district of Maharashtra.