David Jackson

USA TODAY

WASHINGTON — Less than a week after authorizing a missile strike against Syria, President Trump took to social media Tuesday to rattle the saber at North Korea and its nuclear program.

"North Korea is looking for trouble," Trump tweeted. "If China decides to help, that would be great. If not, we will solve the problem without them! U.S.A."

The tweet also came less than a week after Trump met with China President Xi Jinping and urged his country to rein in North Korea over its missile tests and threats to use nuclear weapons.

In a separate tweet, Trump said he explained to Xi that "a trade deal with the U.S. will be far better for them if they solve the North Korean problem!"

Trump has not commented publicly in recent days on next steps in Syria, though aides have said he is prepared to strike them again if Syrian President Bashar Assad's government again uses chemical weapons.

The cruise missile strike against a Syrian air base destroyed some buildings and warplanes, but the runway was left intact, and Syrian planes flew from days later.

Trump's comments about North Korea and China came hours after North Korea attacked the movement of a U.S. naval strike group into the region and said it is ready for "war.''

A spokesman for Kim Jong-Un's government told state media that the U.S. strike force movement "goes to prove that the U.S. reckless moves for invading the DPRK have reached a serious phase."

The spokesman added: "The DPRK is ready to react to any mode of war desired by the U.S."