It will be the largest global gathering on US soil in 65 years. President Barack Obama's two-day nuclear security summit, involving 47 countries, gets under way in Washington DC on Monday.
On the sidelines of what is expected to be the biggest gathering of world leaders led by a US president since the signing of the UN charter in San Francisco in 1945,
Obama will hold bilateral meetings with several leaders, including Manmohan Singh and Yousuf Raza Gilani, respectively the prime ministers of India and Pakistan.
The US administration is trying to balance its policies in Afghanistan with the rising ambitions of the two neighbours.
Robert Wirsing, an South Asia security analyst and professor of international politics at Georgetown University's Doha campus, explained the challenges facing the US to Al Jazeera's Imran Garda.
