WASHINGTON (January 3, 2013)--Nearly a year after a debilitating stroke, U.S. Sen. Mark Kirk, R-Ill., was back at work Thursday.

He climbed the steps of the Capitol on Thursday to claim his Senate seat.

Vice President Joe Biden greeted Kirk Thursday at the foot of the Capitol steps.

Biden and Democratic Sen. Joe Manchin of West Virginia were at Kirk's side as Kirk used a four-pronged cane to climb the 45 steps, earning rousing applause from fellow senators, the Illinois congressional delegation and others.

Kirk waved, smiled, and paused several times to greet well-wishers.

During his recovery from the stroke, the senator endured an intensive, experimental rehabilitation regimen that is often compared with military boot camp because of its intensity.