04 April 2016 Current Affairs: Prime Minister Narendra Modi on 4 April 2016 returned to New Delhi after concluding his official visit to Belgium, United States and Saudi Arabia.During the five day tour from 30 March to 3 April 2016 Modi met several leaders and also participated in two different summits, namely India-EU summit in Brussels and 4th Nuclear Security Summit in Washington DC.Belgium : In the first leg of his visit to Belgium, Modi was given a ceremonial welcome at Egmont Palace in Brussels. Brussels is the headquarters of European Union and NATO.He attended 13th India-EU summit and held meeting with Belgium Prime Minister Charles MichelFrom Belgium, he also activated Asia's largest 'general purpose' optical telescope installed in 'Devsthal', 60 km from Nainital, through 'Remote Technical Activation'During the visit, the two nations released a joint statement and an agenda that will serve as a roadmap for EU-India cooperation in what is referred to as Action 2020.The Joint Declaration on the India-EU Water Partnership was adopted to enhance cooperation on environment issues, including on the ‘Clean India' and ‘Clean Ganga’ flagship programmes.The EU-India strategic partnership was launched in 2004. The last summit was held in Delhi in 2012.United States : In the second leg of his tour to three nations, Modi visited the United States where he attended the 4th Nuclear Security Summit in Washington DC. The summit focused on a gamut of issues pertaining to nuclear security.The two-day summit highlighted achievements and commitments of several countries towards safeguarding nuclear devices and technologies and reducing the threat of nuclear terrorism. He also announced a contribution of 1 million US dollars to Nuclear Security Fund of International Atomic Energy Agency.India, US signed MoU for setting up Laser Interferometer Gravitational-wave Observatory (LIGO) observatory in India.Saudi Arabia : Prime Minister inspected the guard of honour at the Ceremonial Welcome in Riyadh. India and Saudi Arabia signed five agreements and MoUs.During the visit, Modi met with Saudi King Salman bin Abdulaziz Al Saud a gold-plated replica of the Cheraman Juma Masjid of Kerala. Situated in Thrissur district, the mosque is believed to be the first mosque built in India by Arab traders around 629 AD.He also met with other ministers of the nation and invited Saudi Arabia's top business tycoons to invest in India's key sectors like defence, insurance, railway and oil.He interacted with the business leaders at Saudi Chambers of Commerce and Industry in Riyadh during his visit to Saudi Arabia.He visited TCS All Women IT Centre and Masmak Fortress in Riyadh.