Following his official engagements, Modi visited a temple and interacted with the Indian community here before embarking for the USA on the second leg of his three-nation tour.
India, a big buyer of the U.S. arms that was recently named by Washington as a major defence ally, wants to protect its 7,500- km (4,700-mile) coastline as Beijing expands its maritime trade routes and Chinese submarines increasingly lurk in regional waters.
Modi, who arrived here on the first leg of his three- nation tour, said his brief visit will further strengthen relations between India and Portugal.
The two leaders will hold talks on Monday afternoon in the White House and would spend several hours together in various settings including one-on-one and delegation level meetings, a reception and a working dinner.
In a development that will provide a boost to India's maritime security, the Trump administration has authorised the sale of unarmed surveillance drones to India, the manufacturer said on Friday, as the two nations' leaders prepare for their first face-to-face meeting. "We very much want to avoid a situation that escalates tensions between the two", said the White House official. Apart from official meetings with Trump and his cabinet colleagues, Modi will be meeting some prominent American CEOs.
The Indian delegation also want to gain a sense of Mr Trump's strategic plans in India's neighbourhood, and whether he wants to keep on maintaining the balance of power in that part of Asia, as the United States has done for decades.
India's Prime Minister Narendra Modi and Portuguese Prime Minister Antonio Costa, right, ar given ceremonial shawls during a visit to the Radha Krishna Temple in Lisbon, Portugal, Saturday June 24, 2017.
The two agreed that the two countries have a deep and growing strategic partnership and hope to work more closely on regional and global issues.
On foreign policy in particular, Mr Trump has "sidelined the state department and other agencies", Mr Xavier said.
Ahead of his visit, Modi yesterday said he looked forward to the opportunity of having an in-depth exchange of views.
In a statement posted on the Facebook, Modi said his two-day visit to Washington from June 25 was at the invitation of Trump. Our conversations have touched upon our common intent to take forward our productive all round engagement for the mutual benefit of our people....
The decision to launch the startup hub was taken during Portuguese Prime Minister Antonio Costa's visit to India in January this year.