TOKYO (Kyodo) -- Prime Minister Shigeru Ishiba on Monday urged U.S. President Joe Biden to address concerns in business circles triggered by his blocking of a takeover of United States Steel Corp. by a Japanese competitor, saying an investment-friendly environment is critical for allies and partners to ensure economic security.

Ishiba made the remarks during a virtual trilateral summit that also involved Philippine President Ferdinand Marcos Jr., where the three leaders agreed to continue cooperating in addressing security issues, developing robust infrastructure and realizing a rules-based order in the Indo-Pacific region.

Biden has blocked the envisaged U.S. Steel buyout by Japan's Nippon Steel Corp. on national security grounds. Before Monday's virtual meeting, Ishiba said Japan, a longtime U.S. security ally, would seek clarity over why Biden reached that decision.

During the roughly 25-minute conversation, Ishiba stressed the importance of cooperation among allies and like-minded partners in building robust supply chains and making their countries investment-friendly for companies to ensure economic security, according to the Japanese Foreign Ministry.

The online summit came before U.S. President-elect Donald Trump returns to the White House on Jan. 20, replacing Biden. The outgoing president hosted the first-ever summit of the United States, Japan and the Philippines, two of its Asian allies, in April last year.

The three leaders confirmed Monday that they will jointly counter economic coercion and unilateral attempts to change the status quo by force, the ministry said, in an apparent reference to China.

"We confirmed that progress has been made on ensuring maritime and economic security and making infrastructure resilient and agreed to continue working together," Ishiba told reporters after the trilateral summit.

"We will make further efforts to realize a free and open Indo-Pacific based on the rule of law," said Ishiba, who has described the security environment surrounding Japan as increasingly "severe and complex."

Chinese ships continue to enter waters around the Japanese-administered Senkaku Islands in the East China Sea, uninhabited islets claimed by China. The Philippines has a territorial dispute with China over the Spratly Islands in the South China Sea.

The White House said the three leaders discussed China's "dangerous and unlawful behavior in the South China Sea," in addition to their maritime security and economic cooperation.

It added that they agreed on the importance of continued coordination to promote a free and open Indo-Pacific.

Ishiba is considering visiting the United States before mid-February for a summit with Trump, according to Japanese government sources.

The Japanese premier said Monday his government is "making final arrangements" to meet with Trump "at an early date."