Meeting with the king at the Sunnylands estate in Southern California Friday night, Obama pledged to support Jordan's stressed economy with $1 billion in loan guarantees, the New York Times reported.
The current aid package, valued at $660 million, is set to expire in September.
Obama told reporters it is "very important for us to make sure that we're supportive of the kingdom in accommodating all these refugees."
"In a region that obviously is going through enormous changes, the friendship between our peoples has been a constant," the president said.
Noting that Jordan will soon take a seat on the U.N. Security Council, Obama said the United States and Jordan would be focusing attention on the situation in Syria.
The president said he and the king "recognize we can't just treat the symptoms" of the crisis in Syria, but that a "political transition" was needed.
While Jordan faces many challenges in dealing with the crush of Syrian refugees, the king said "we see ourselves as an oasis of stability to our neighbors."
He praised the United States for going "beyond the call of duty in its support for us."