Japan's leaders need to take U.S. President Donald Trump seriously, but not always literally, and must exercise great caution in interpreting what he says. But Japan must also stress to him the importance, and benefits, of the U.S.-Japan security and economic relationship.

That was the message from participants during a session on Trump and security relations Thursday at the opening day of the annual Kansai Economic Seminar.

With Prime Minister Shinzo Abe due to meet the U.S. president Friday in Washington, the future direction of U.S.-Japan relations, and Europe after Brexit, were the main areas of concern and unease among many of the seminar's nearly 530 participants, most of whom are executives of some of the largest firms from Kansai and Japan as a whole.