JACKSONVILLE, Fla. -- President Obama pledged on Monday not to "rush the solemn decision" to send more troops to battle in Afghanistan as he weighs military options on what to do next in the troubled war.

"I won't risk your lives unless it is absolutely necessary," Obama told service men and women at Naval Air Station Jacksonville. He promised a "clear mission" with defined goals and the equipment needed to get the job done.

Obama, who is in the process of weighing options put forward by the Pentagon that include various levels of increased troops, spoke of the latest example of the dangers and sacrifices there -- helicopter crashes that killed 14 Americans in the deadliest day for the U.S. mission in Afghanistan in more than four years...