Yemen\'s President Ali Abdullah Saleh will stay in the United States beyond the election next month that will choose his successor, a senior diplomatic source said Wednesday. Saleh headed for the United States from Oman on Wednesday to seek medical treatment for injuries suffered in a rocket attack on his palace last year before he agreed to step aside. \"Saleh will stay in the United States until at least February 21,\" the diplomatic source, close to negotiations that led to the president\'s departure, told AFP. A presidential election is to be held on that date. \"He will not be admitted to a hospital but will see consultants in New York,\" said the source, who spoke on condition of anonymity because of the confidentiality of the negotiations. Saleh suffered blast wounds from a bombing at the presidential palace in June last year. Diplomatic sources said serious burns were inflicted. After months of deadly protests, the Yemeni leader finally signed up to a power transfer deal in November that effectively ended his three decades in power. He left Sanaa for Oman on Sunday with members of his family. The Yemeni embassy in Washington has said Saleh will be on \"a private medical visit\" to the United States and will return to Yemen \"in February\" to attend the swearing-in ceremony of the new president. UN envoy to Yemen, Jamal Benomar, expressed disappointment meanwhile with a law passed by the Yemeni parliament last week which confirms an immunity deal given to Saleh. \"I told all our Yemeni counterparts that despite all these changes in the law, the final draft doesn\'t conform to what we had hoped for in terms of compliance with international standards,\" Benomar said after briefing the Security Council. The council also said in a statement that \"all those responsible for human rights abuses, including acts of violence, must be held accountable.\" There has been strong criticism from demonstrators of the immunity deal under which Saleh handed over power and left the country. But Benomar said that after 11 months of unrest, \"the transition is on track\" and he was confident the election would be held. The envoy said there is \"very volatile\" security in Yemen with an insurgency in the north, Al-Qaeda expanding its reach in the south and near famine conditions in much of the country that now affect about 500,000 children. The Security Council statement expressed concern at the \"deteriorating\" security in Yemen and the growing presence of Al-Qaeda. The 15-nation body said the election marks the start of a \"new era\" for Yemen but called for a \"credible, peaceful, non-violent\" vote.