TOKYO (AP) — Japanese Prime Minsiter Shigeru Ishiba on Thursday showed his determination to defend rules-based free and multilateral trade systems and take a leadership role to expand the Asia-Pacific trade group at a time of deepening tensions and divisions over U.S. tariffs and trade wars.

“High tariffs will not bring economic prosperity," Ishiba told a global forum in Tokyo. "A prosperity built on sacrifices by someone or another country will not make a strong economy."

Japan seeks to work with the U.S. on investment, job creation and manufacturing high quality products for the prosperity of America and the rest of the world, he said.

His comment comes as Japan’s chief tariff negotiator Ryosei Akazawa travels to Washington, D.C., for a fourth round of talks attempting to convince the U.S. to drop all recent tariff measures. So far Japan has not been successful in gaining U.S. concessions and is reportedly considering purchases of more U.S. farm products and defense equipment as bargaining chips.

Akazawa told reporters that defense equipment purchases could “come into view” during the talks because Japan's purhases of defense equipment would contriubute to the U.S. trade surplus, though Japanese security policy is not subject to "a deal” with another country.

Ishiba also called on other countries in Asia, a global hub of growth, to show “the importance of rules-based, free and fair economic order," and said the way to demonstrate it is the Comprehensive and Progressive Agreement for Trans-Pacific Partnership, or CPTPP.

Ishiba pledged Japan will work toward further expanding and upgrading the framework, which not only contributes to the economy but also to peace and prosperity.

The 12-nation CPTPP includes Japan, the United Kingdom, New Zealand, Australia, Brunei, Canada, Chile, Malaysia, Mexico, Peru, Singapore and Vietnam. The U.S. is not a member.

While Tokyo is strengthening economic ties with Southeast Asia and Europe, Japan still considers the United States as its lynchpin of security policies and is not walking away from their alliance.