Moscow, April 20, SPA -- U.S. Secretary of State Condoleezza Rice on Tuesday called the Kremlin's tight grip on power and the media "very worrying" and urged Russian President Vladimir Putin not to cling on to power beyond his present term. Rice made some of the sharpest U.S. criticism to date of the Kremlin's record on democracy at the start of a visit to Moscow, the first by the former Soviet specialist since being confirmed as President Bush's foreign minister. Her two-day trip got off to a shaky start when a bomb threat forced her motorcade to divert as it took her to her hotel from the airport. "There was a bomb threat called into the hotel. She has gone to the ambassador's residence," said a senior U.S. official who asked not to be named. Security services checked the hotel, but no bomb was found, Reuters quoted a U.S. official as saying. With meetings scheduled with senior Russian officials including Putin on Wednesday, Rice told reporters on board her plane as she flew in to Moscow: "Trends have not been positive on the democratic side." "The centralization of state power in the presidency at the expense of countervailing institutions like the Duma [parliament lower house] or an independent judiciary is clearly very worrying," she added. Even more pointedly, she also said it "would not be a positive development" if Putin changed the constitution to be able to run for a third successive term.--SPA1058 Local Time 0758 GMT www.spa.gov.sa/256536