WASHINGTON (AP) — President Donald Trump has endorsed Marsha Blackburn in the Republican primary for a U.S. Senate seat from Tennessee.

Trump tweeted Thursday that the sitting congresswoman is a "wonderful woman who has always been there when we have needed her." Trump said she's great on his key issues of the military, border security and crime and "loves and works hard for the people of Tennessee."

Trump said, "I will be there to campaign with her!" He did not announce any dates.

Blackburn faces former Republican U.S. Rep. Stephen Fincher in the August GOP primary. The seat became open when incumbent Sen. Bob Corker, a Trump critic, announced his retirement.

Former Tennessee Gov. Phil Bredesen is the Democratic candidate.

Republicans hold a slim 51-49 advantage in the U.S. Senate.