US President Barack Obama will leave Andrews Air Force Base this evening for his highly anticipated three-day landmark trip to India on an invitation by Indian Prime Minister Narendra Modi. The capital is under the highest level of security and is seeing unprecedented measures for President Obama's visit. For President Obama, who is the chief guest of the Republic Day celebrations, security agencies in New Delhi have extended the 300 km no-fly zone during the Republic Day to a radius of 400 km this year, covering cities such as Jaipur in the west, and Agra, and extending to the border with Pakistan.