Hillary Clinton picks Senator Tim Kaine for running mate: official

Hillary Clinton announced Friday she has chosen Tim Kaine, a Spanish-speaking senator from the battleground state of Virginia, to be her White House running mate.

"I'm thrilled to announce my running mate, @timkaine, a man who's devoted his life to fighting for others. -H," the presumptive Democratic nominee tweeted.

In a second Twitter message, Clinton heaped praised on Kaine, 58, known for his affable manner and expertise on matters of defense and foreign policy.

"@TimKaine is a relentless optimist who believes no problem is unsolvable if you put in the work to solve it," Clinton wrote.

Kaine, who currently serves on the Senate Foreign Relations and Armed Services committees, could help Clinton bring in two key voting blocs: Hispanics and the battleground state of Virginia.

Politically a middle-of-the-road Democrat, he is also seen as helping Clinton win votes from independent male voters.

The pick comes just days before the start of the Democratic National Convention in Philadelphia, where Clinton -- and now Kaine -- next week are to be elevated as the nominees to the party's presidential ticket.