Japanese Finance Minister Taro Aso said on Friday he wants to use the U.S.-Japan economic dialogue as a platform to discuss rules for free trade and investment.

Aso said the dialogue would discuss economic policy, infrastructure and energy, but it is difficult to offer more details because U.S. President Donald Trump’s administration is yet to fill some vacant positions.

“I want to discuss rules for free and fair trade and investment and hope that these rules can be spread throughout the world,” Aso said.

Japanese Prime Minister Shinzo Abe and Trump agreed last month to establish a new framework for economic dialogue to discuss trade and infrastructure investment to be chaired by Aso and U.S. Vice President Mike Pence.

Japanese media have reported that Pence will visit Tokyo next month, but the White House has yet to make an official announcement.

Shortly after taking office in January, Trump shocked Japanese policymakers by saying the Bank of Japan’s monetary easing amounts to currency manipulation and complaining about the low number of U.S. auto exports to Japan.

Trump has since softened his tone on Japan, but there are concerns that the United States could adopt protectionist policies in the future to fulfill his pledge to make U.S. companies more competitive.

The economic dialogue between the two countries is seen as a test of whether the United States and Japan can maintain good economic ties under the new U.S. administration