The most urgent problem facing Trump and Xi is how to persuade nuclear-armed North Korea to halt unpredictable behavior like missile test launches that have heightened tensions in South Korea and Japan, Reuters reports.

North Korea is working to develop an intercontinental ballistic missile capable of hitting the United States.

The White House has said North Korea was a test for the U.S.-China relationship, and Trump has threatened to use trade to try to force China to exert influence over Pyongyang.

"I think China will be stepping up," Trump told reporters. Beijing says its influence is limited and that it is doing all it can but that it is up to the United States to find a way back to talks with North Korea.

Trump consulted on Wednesday with Japanese Prime Minister Shinzo Abe, who said he and the president agreed by phone that North Korea's latest ballistic missile launch was "a dangerous provocation and a serious threat."

A White House strategy review is focusing on options for pressuring Pyongyang economically and militarily. Among measures under consideration are "secondary sanctions" against Chinese banks and firms that do the most business with Pyongyang.

A long-standing option of pre-emptive strikes remains on the table, but despite the tougher recent U.S. talk, the internal review "emphasises direct military action," a U.S. official said, speaking on condition of anonymity.

Analysts believe any military action would likely provoke severe North Korean retaliation and massive casualties in South Korea and Japan and among U.S. troops stationed there.

Here is the arrival of the Chinese president's plane in Florida: