More foreign fighters, including al-Qaida militants, are operating in Pakistan's tribal areas than in the past, underscoring the need for Pakistan to crack down on insurgent safe havens, the top US military officer said during a visit here. Adm. Mike Mullen said militants are flowing into Afghanistan more freely this year compared with last year because Pakistan's government and military are not putting enough pressure on insurgents. Mullen said that a recent pact Pakistan's government made to go after militants who don't agree to lay down their weapons could be useful if it's enforced. Previous peace deals in Pakistan's tribal areas only gave insurgents freedom to carry out militant operations. "There are clearly more foreign fighters in the FATA (Pakistan's Federally Administered Tribal Areas) than have been there in the past," he added. "What it really speaks to is that's a safe haven and it's got to be eliminated for all insurgents, not just al-Qaida, although al-Qaida certainly is a top priority because of the threat al-Qaida represents." Attacks in eastern Afghanistan, where U.S. forces operate along the border with Pakistan, are up 40 percent this year compared with last year, and June was the deadliest month for US and NATO soldiers in Afghanistan since the 2001 US-led invasion. Militant attacks are becoming more complex, intense and better coordinated than a year ago, Mullen said.