CAMP LEJEUNE, N.C. - The nation's highest-ranking military officer told soldiers and Marines yesterday that the insurgency in Afghanistan has grown in the last three years and he expects casualties to rise next year as more U.S. troops pour into the war.

"This is the most dangerous time I've seen growing up the last four decades in uniform," Adm. Mike Mullen, chairman of the Joint Chiefs of Staff, told about 1,000 Marines at Camp Lejeune.

Many attending Mullen's talks at Camp Lejeune and Fort Campbell, Ky., will be sent to Afghanistan in President Obama's plan announced last week.

After the first of the year, the Marines will begin sending an additional 6,200 from Lejeune and Camp Pendleton, Calif., the Pentagon announced yesterday. The Army will also begin sending in the first of its forces in the spring - a training brigade with about 3,400 soldiers from Fort Drum, N.Y. Three brigades from Fort Campbell's 101st Airborne Division are also heading to Afghanistan and about 4,100 support forces from various places will deploy early.

"We are not winning, which means we are losing and as we are losing, the message traffic out there to [insurgency] recruits keeps getting better and better and more keep coming," Mullen said. "That's why we need the 30,000 and in particular, and you are the lead on this, getting in there this year, over the next 12 months, almost in lightning-bolt fashion."

Mullen told 700 soldiers at Fort Campbell that military leaders believe they have 18 to 24 months to reverse the insurgency, in what he expects to be a tough and bloody fight.

"I am sure we will sustain an increase in the level of casualties, and I don't want to be in any way unclear about that," he told troops at Fort Campbell. "This is what happened in Iraq during the surge and as tragic as it is, to turn this thing around, it will be a part of this surge, as well."

"I expect a tough fight in 2010," Mullen said.

(The U.S. military reported the death Saturday of a soldier killed Saturday by a bomb blast while on foot patrol in eastern Afghanistan.)

Camp Lejeune will supply 1,500 Marines by Christmas. An additional 6,200 are to follow next year. Pvt. William Schneider, 20, from Woodbridge, N.J., expects to deploy early next year. As a new rifleman, the deployment will be his first.

"This is what we've been training up for nine months. We want to put our training to use," Schneider said.

Many questions from soldiers and Marines focused on the role of Pakistan and America's NATO allies in containing al Qaeda and the Taliban.

Mullen said the border between Afghanistan and Pakistan is "the epicenter for global terrorism."