>> hey lady! this is the "cbs weekend news." >> quijano: good evening, i'm elaine quijano. exactly seven months into his presidency, with his economic agenda eclipsed by political turmoil, president trump is shifting focus to america's longest war. the president will address the nation monday night with a new strategy for the war in afghanistan. it could include sending thousands more u.s. troops. during his presidential campaign, mr. trump repeatedly criticized the length of the conflict. since 2001, more than 2,400 u.s. troops have been killed there. another 20,000, wounded. the 16-year war has cost american taxpayers more than $800 billion. here's errol barnett. >> reporter: sources tell cbs news the strategy allows for deploig around 4,000 new troops and aggressively pushing pakistan for being a safe haven for terrorists.