evidence: Over Rs 640 crore has been spent on PM's foreign trips since 2004 [...] Singh has surpassed Vajpayee and many other former prime ministers, earning the tag of "non-resident Prime Minister" with over 70 foreign trips and nearly Rs 650 crore spent on his travel since 2004, when he was sworn in as Prime Minister for the first time. In his second term, Singh has already made 36 foreign tours and embarked on 37th on Sunday, leaving on a five- day visit to Russia and China. [...] The list of Singh's visits shows the highest expenditure of Rs 26.94 crore during his seven- day visit to Mexico and Brazil in 2012 to attend G20 and Rio+ 20 Summit. This is followed by Rs 22.7 crore spent on travel to the USA and Brazil in 2010, when he had gone to attend the Nuclear Security Summit, BRIC Summit and IBSA Summit.