EDGARTOWN, Mass., Dhu-AlQa'dah 8, 1436, Aug 23, 2015, SPA --U.S. Vice President Joe Biden met on Saturday with Senator Elizabeth Warren, a popular progressive leader with a big support base among Democrats, as he mulls whether to run for president, according to a source familiar with the matter, Reuters reported. Biden has been huddling with senior advisers to evaluate options for taking on former Secretary of State Hillary Clinton, the Democratic front-runner who has struggled to overcome fallout from her use of a private email server while working as the nation's top diplomat. -- SPA 03:44 LOCAL TIME 00:44 GMT www.spa.gov.sa/w