Modi, upon arrival, was received by External Affairs Minister Sushma Swaraj.
The highlight of his four-day trip was the US leg of the visit as Modi met President Donald Trump for the first time on June 26 in Washington.
In the US, Modi held talks with Trump during which the two leaders vowed to strengthen cooperation on terror. India and the US also urged Pakistan to ensure that its territory is not used to launch cross-border terror strikes.
Modi first visited Portugal, where he held wide ranging talks with his counterpart Antonio Costa. He also addressed the Indian community there and presented the Overseas Citizen of India card to Costa.