U.S. Trade Representative Robert Zoellick warned Japan on Friday not to take retaliatory action against the United States over its decision to impose tariffs on a range of steel imports, Japanese government officials said.

Zoellick issued the remarks during a 25-minute telephone conversation with Foreign Minister Yoriko Kawaguchi, the officials said.

The United States on March 20 said it was following World Trade Organization guidelines in imposing safeguard tariffs of up to 30 percent on a range of steel imports, ostensibly to protect antiquated U.S. steel mills.