Paul Ryan is Romney VP Pick
Announcement made to supporters via phone app.
US Republican presidential candidate Mitt Romney has named fiscal conservative Paul Ryan as his running mate in November's election.
Mr Ryan, 42, is a congressman for his home state of Wisconsin.
Ohio Senator Rob Portman and former Minnesota governor Tim Pawlenty had also been tipped to run with Mr Romney as vice-presidential candidate.
The BBC's North America Editor Mark Mardell says the decision is a bold and ideological choice.