A defiant North Korea and global terrorism were the main focus of talks at the fourth Nuclear Security Summit (NSS) in Washington.
The two-day biennial summit opened on Thursday night with a welcome dinner at the White House for the over 50 top world leaders, including Prime Minister Narendra Modi, media reports said.
US President Barack Obama, who launched the summit in 2010 and is hosting his fourth and last such summit, said there is "great urgency" to end the scourge of global terrorism after the March 22 Brussels attacks in which 32 people were killed and the Paris attacks in November last year that claimed 130 lives.
Obama was flanked by PM Narendra Modi to the left and Chinese President Xi Jinping on the other side during the NSS working dinner to discuss how to prevent terrorists and other non-state actors from gaining access to nuclear materials.
Xi and Obama found common ground on confronting the nuclear threat posed by North Korea. China supported a new round of UN sanctions against the Pyongyang government after it tested a nuclear device and fired ballistic missiles, the New York Times reported.
Obama also met Prime Minister Shinzo Abe of Japan and South Korea's President Park Geun-hye.
In a meeting prior to the dinner on Thursday evening, Obama praised his French counterpart Francois Hollande for "galvanising the European community" in the fight against terror groups. Both leaders also discussed ways to strengthen bilateral cooperation to prevent further terrorist attacks, EFE news reported.
Russia, the country with the largest nuclear weapons arsenal in the world, has decided not to attend the summit citing "lack of cooperation" between partners, according to Kremlin spokesman Dmitri Peskov.
Russia's absence makes it difficult to reach major agreements on nuclear safety.
Nine countries—the US, Russia, Britain, France, China, India, Pakistan, Israel and North Korea— together possess more than 15,000 nuclear weapons, but 90 per cent of all nuclear weapons are in the US and Russia.
Besides Hollande, Xi and Modi, British Prime Minister David Cameron, Turkish President Recep Tayyip Erdogan and Kazakhstan President Nursultan Nazarbayev are also attending the summit.
Pakistan Prime Minister Nawaz Sharif was due to participate in the summit but he cancelled his visit in the backdrop of the deadly suicide attack at Gulshan-e-Iqbal Park in Lahore on March 27, in which at least 72 people, including 29 children, were killed and over 300 others injured.
However, Minister of State and Special Assistant to the Prime Minister Syed Tariq Fatemi will represent Pakistan at the Summit.
The first of these biennial nuclear security summits was held in Washington in April 2010, followed by summits in Seoul in March 2012 and The Hague in March 2014.
US Secretary of State John Kerry and Secretary of Energy Ernest Moniz co-hosted a separate working dinner for other members of the visiting delegations.