Sen. John McCain announces he’s running for 6th term

U.S. Sen. John McCain, R-Ariz. is shown in this March 2015 file photo. McCain announced Tuesday that he will seek a 6th term in the Senate.

U.S. Sen. John McCain says he will run for re-election.

The Arizona Republican tells NBC News in an interview that he plans to run for a sixth term in 2016. He is the chairman of the Senate Armed Services Committee.

Tea party groups see him as a top challenge in a primary. Conservatives have criticized him as too moderate. The 78-year-old will be 80 by Election Day, but he says his Senate career is only beginning.

McCain ran for president in 2008.