Nicholas Burns, the third ranking US diplomat who served as the point man on the US push to enact UN sanctions on Iran and negotiate a nuclear cooperation agreement with India, announced Friday that he was resigning from his post, according to dpa. Burns has served as undersecretary for political affairs since March of 2005, overseeing US foreign policy in each region of the world. Burns, 51, told reporters he was stepping down to spend more time with his family. Burns served as the permanent US representative to NATO prior to his current job, and had previously served as ambassador to Greece, State Department spokesman and on the National Security Council. Burns spearheaded US negotiations with the other four members of the UN Security Council to enact two rounds of sanctions on Iran because of the Islamic state's refusal to suspend uranium enrichment. He also completed complex and difficult negotiations with India to hammer out an agreement allowing the United States to share civilian nuclear energy technology with India. US President George W Bush and Indian Prime Minister Manmohan Singh signed the deal in March 2006, but its implementation has been held up because of differences in India's coalition government.