TOKYO (Kyodo) -- Japanese trade minister Ryosei Akazawa on Wednesday expressed hope to hold "in-depth" discussions with his U.S. counterpart on finalizing the first project under a $550 billion investment plan agreed as part of a bilateral tariff deal.

At Tokyo's Haneda airport before his departure to the United States, Akazawa told reporters that if he reaches an agreement with U.S. Commerce Secretary Howard Lutnick, he will announce it "as soon as possible."

Akazawa led Japan-U.S. tariff negotiations as economic revitalization minister under former Prime Minister Shigeru Ishiba. His trip marks his first visit to the United States as trade minister under Prime Minister Sanae Takaichi, Ishiba's immediate successor.

"We have already held a considerable number of discussions," Akazawa, who is scheduled to return to Japan on Saturday. He added that the talks "will not be straightforward." In return for reduced U.S. tariff rates, Japan has pledged to invest in the United States.

Gas-fired power generation, synthetic diamond production and port development projects are among the leading candidates for the first investment. Akazawa and Lutnick are set to settle on specific projects, with U.S. President Donald Trump making the final decision.