Prime Minister Lee Hsien Loong is in the United States for a week-long working visit that will include meetings with US leaders and participation in the fourth Nuclear Security Summit.
Mr Lee's visit begins today in New York, where he will meet strategic thinkers as well as industry and financial-sector leaders, the Prime Minister's Office said. He will also attend a reception with Singaporeans living in New York and visit the Sept 11 memorial.
Mr Lee will then travel to Washington, where he will meet Federal Reserve chairman Janet Yellen and attend the Nuclear Security Summit from March 31 to April 1.
Although Singapore has limited nuclear ambitions, Mr Lee has attended all three previous summits in 2010, 2012 and 2014 in a signal of the country's commitment to nu- clear security and its concern about the threat of nuclear proliferation.
Leaders from more than 50 countries, including Chinese President Xi Jinping, Indian Prime Minister Narendra Modi and South Korean President Park Geun Hye, are expected to attend the summit.
According to the White House, the summit will continue discussions on the evolving threat and highlight steps that can be taken together to minimise the use of highly enriched uranium, secure vulnerable materials, counter nuclear smuggling and deter, detect and disrupt attempts at nuclear terrorism. Leaders will also discuss ways to further strengthen the global nuclear security architecture.
The recent nuclear and missile tests by North Korea are expected to be high on the agenda.
Earlier this month, the United Nations Security Council approved the toughest sanctions imposed on the communist state in 20 years, in response to its nuclear test and a satellite launch early this year.
This is Mr Lee's second visit to the US this year. In February, he met technology leaders in San Francisco and attended the Asean-US Summit at the Sunnylands estate.
On this trip, he is accompanied by Mrs Lee and senior government officials.
During his absence, Deputy Prime Minister and Coordinating Minister for National Security Teo Chee Hean will be Acting Prime Minister.