TOKYO (AP) — Vice President Mike Pence said the U.S. is preparing to announce the "toughest and most aggressive" economic sanctions against North Korea in the coming days, boosting pressure on the bellicose government during the Winter Olympics.

Pence, who is set to lead the U.S. delegation at the opening ceremonies Friday, made the announcement in Japan on Wednesday, following meetings with Prime Minister Shinzo Abe.

"The United States of America will soon unveil the toughest and most aggressive round of economic sanctions on North Korea ever — and we will continue to isolate North Korea unti...