WASHINGTON " The highest-ranking U.S. military officer warned Thursday that the situation in Afghanistan will likely get worse next year and that it will take time to turn it around because it has been headed in "the wrong direction" for the last two years. Admiral Michael Mullen, chairman of the Joint Chiefs of Staff, said that U.S.-led forces are "not going to be able to kill our way to victory in Pakistan and Afghanistan" and a new strategy is needed to suppress a resurgent Taliban movement before it's too late. Violence has increased markedly since 2006 and "the trends are going in the wrong direction unless we take significant steps," Adm. Mullen told reporters at a breakfast hosted by the Christian Science Monitor. The security situation in Afghanistan cannot improve until there's economic and political development in Afghanistan and the U.S. and its coalition partners have embraced a strategy that links Afghan and Pakistani issues, he said. "The trends across the board are not going in the right direction," Mullen said at a breakfast with reporters this morning. "It will be tougher next year unless we get at all these challenges." The chairman's comments reflect a growing worry among Pentagon officials that the U.S. military cannot sustain troop levels in Iraq and also address the worsening violence in Afghanistan . While violence has dropped significantly in Iraq this year, it's risen by roughly 30 percent in Afghanistan , and U.S. troop deaths in Afghanistan now surpass the monthly toll in Iraq . Last week, Gen. David McKiernan , the top U.S. commander in Afghanistan , also said the situation would likely worsen. McKiernan has asked for three more combat brigades. Afghanistan has had a far lower priority in troops and funds than Iraq has, and it's frequently referred to as an "economy of force" operation, one that requires a minimal number of troops. But top Pentagon officials say it can't be run that way any longer, and the military has recently begun to re-examine its Afghan strategy. Most military analysts agree that while 42 countries have sent troops to Afghanistan , there are not enough. On Wednesday, Secretary of Defence Robert Gates asked attendees at a meeting of Southeast European defense ministers to supply more troops for Afghanistan . Both Barack Obama and John McCain have called for more troops in Afghanistan , but the military says they must first reduce U.S. forces levels in Iraq . There are roughly 152,000 troops in Iraq and 33,000 in Afghanistan .