July 2, 2009 U.S. soldier captured by Taliban; demand for quid pro quo Play video

(NECN/ABC) - A U.S. soldier was captured and held by insurgents in Afghanistan on Thursday.

The U.S. Military said it was not related to a major offensive begun there against the Taliban -- Operation Strike of the Sword -- the biggest military offensive of Barack Obama's presidency. It began in the dead of night.

Four thousand U.S. troops poured into southern Afghanistan's Taliban stronghold: Helmand Province.

More opium is produced there than anywhere else in the world.

To take control of the region, U.S. forces abandoned conventional war tactics. They fought locally alongside a small number of U.S.-trained Afghans.

The strategy is similar to the surge in Iraq. Thursday in Nawa, American soldiers took insurgents by surprise.

"The aim of the assault was to put Marine Corps forces back expeditionary- wise out behind enemy lines," USMC Capt. Drew Schoenmaker said. "We dropped in to a few places that nobody had been."

U.S. forces in Afghanistan will reach 62,000 by 2010, more than double the troop levels at the start of this year.

One commander said the aim is to go big, go strong, and go fast to wrest control back from the Taliban.

Insurgent violence in Helmand province is at its highest point since 2001.

In eastern Afghanistan, a U.S. soldier was taken into Taliban custody in Patika, near the Pakistan border.

There are questions regarding just how the soldier got into

American officials said they were doing all they can to secure the soldier's release.

The Taliban is demanding the release of all of its fighters as a quid pro quo.

ABC's Gloria Riviera reports.