Matthew Pennington, The Associated Press

WASHINGTON (AP) " President Donald Trump is leaving himself plenty of wiggle room when it comes to following through with a summit with the leader of North Korea, telling reporters that he will bail out of the meeting if he decides it won't produce results.

Discussing the planned sit-down with North Korean Kim Jong Un during a joint news conference Wednesday alongside Japan's prime minister, Trump said he could end up leaving the meeting with Kim early or not go at all. Yet he also sounded optimistic that a summit would prove worthwhile.

In the meantime, Trump said a U.S.-led "maximum pressure" campaign of tough economic sanctions on North Korea will continue until the isolated nation "denuclearizes." Japanese Prime Minister Shinzo Abe agreed, saying there should be no reward for responding to dialogue.