Donald Trump is due to meet some of the 3.4 million Puerto Ricans struggling to recover from Hurricane Maria, as criticism of the federal government's sluggish response continues.
The US President is expected to spend more than five hours on the ground, meeting first responders, local officials and some of the residents struggling to recover from a hurricane that, in Mr Trump's words, left the island territory "flattened".
Mr Trump and First Lady Melania Trump are scheduled to attend briefings, visit a church, and meet Governor Ricardo Rossello, as well as the governor of the US Virgin Islands.
They will also meet Navy and Marine Corps personnel on the flight deck of the USS Kearsarge.