He says Pakistan often gives sanctuary to "agents of chaos, violence and terror," and says the Taliban and other groups there pose a threat to the region and beyond.
Trump is outlining his administration's strategy to the war in neighboring Afghanistan. He says a pillar of that strategy is a change in the U.S. approach to Pakistan.
He adds that Pakistan has much to gain from partnering with the U.S. and much to lose from harboring terrorists.
For years, Washington has criticized Pakistan's tolerance of Taliban militants who launch attacks in Afghanistan. During the Obama administration, restrictions were imposed on military aid to Islamabad because of those concerns.
Defense Secretary Jim Mattis is signaling the U.S. will increase troop numbers in Afghanistan as part of the president's new war strategy.
Mattis says he has directed the chairman of the Joint Chiefs of Staff to prepare to carry out President Trump's plans.
He doesn't speak about the size of a U.S. troop increase.
But he says he'll consult with NATO and U.S. allies, "several of which have also committed to increasing their troop numbers."
Mattis says, "Together, we will assist the Afghan Security forces to destroy the terrorist hub."
