New Delhi, Aug. 30 :    New Delhi, Aug. 30:  Plagued by his knee problem, Prime Minister Atal Behari Vajpayee has deferred by two days his visit to the US and dropped San Francisco from his tour plan. The foreign office said Vajpayee will now leave for New York on the night of September 7, but the change 'would have no bearing on the major elements of his programme'. He is scheduled to address the UN Millennium Summit the next day. He will be in the Big Apple from September 8 to 13 before leaving for Washington for his meeting with President Bill Clinton. Agreeing with his doctors' advice, the Prime Minister has decided to skip San Francisco, where he was to have stayed for four days from September 10 and met, among others, Indian software professionals and barons. Foreign ministry spokesman R.S. Jassal said the Prime Minister's programme in New York would remain unchanged. 'No changes are envisaged in his programme in Washington either in the context of his official visit to the US,' he added. But despite the assurance, the change in the tour programme indicates that the Prime Minister has decided to do away with most of the bilateral meetings that were planned on the sidelines of the UN summit with various heads of governments. If he had stuck to his original programme, he would have had more than two days for meeting the world leaders. By the time Vajpayee arrives in New York, most of the other leaders would be on their way out. Though the Prime Minister's Office insisted that apart from his knee ailment, Vajpayee was all right, the changes in his schedule have strengthened speculation about his health. Signals emerged today that Vajpayee will attend the VHP meet in Staaten Island on September 9. But the Prime Minister, who is not very keen to go there, could cite his knee problem as an excuse for staying there for a short time.