(Reuters) - A suicide bomber killed one American service member and wounded three other U.S. troops outside a base in southern Afghanistan on Thursday shortly after a visit there by U.S. Defense Secretary Leon Panetta, officials said.

Panetta dismissed the attack as a desperate and futile attempt by insurgents to sow chaos in Afghanistan.

He announced that Afghan President Hamid Karzai would head to the United States in the week of Jan 7. for talks with President Barack Obama on the future the U.S. presence in Afghanistan after the NATO-led mission ends in 2014.

But the attack, which was reported to have wounded more than a dozen Afghans, was a reminder of how insurgent violence is still adding to the death toll in the 11-year war -- even as the United States and its allies prepare to hand over security to the Afghans.

"That was the type of attack that we've seen throughout the country," Panetta said. "This is what they resort to in order to try to continue to try to stimulate chaos in this country. They will not be successful at doing that."

Panetta traveled to Afghanistan in part to firm up options to present to Obama about how many troops to keep in the country once the NATO combat mission ends

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