The foreign ministers of Japan and the United States said their countries' ties were stronger than ever on Tuesday, even after Japan's prime minister called U.S. President Joe Biden's decision to block Nippon Steel's $14.9 billion bid for U.S. Steel "perplexing."

Biden's move last Friday was a jolt to U.S. efforts to boost ties just as neighboring South Korea's political crisis potentially complicates a deepening trilateral relationship between Washington, Seoul and Tokyo formed to counter China's growing military power.

On Monday, Japanese Prime Minister Shigeru Ishiba expressed confusion over Biden's decision, but after meeting in Tokyo on Tuesday, U.S. Secretary of State Antony Blinken and Japan's Foreign Minister Takashi Iwaya hailed bilateral ties as stronger than ever.

In remarks to the media, at which no questions were taken, Blinken did not mention Nippon Steel, but a statement from Japan's foreign ministry said he and Iwaya "exchanged views on the economy, including on the acquisition of United States Steel Corporation by Nippon Steel Corporation."

It said they "reaffirmed the importance of Japan-U.S. economic relations, including investments by Japanese companies in the U.S."

Blinken said the two countries were "leading the way" in cooperation between like-minded countries and added: "I have great confidence that will continue for many, many years to come."

After meeting Ishiba at his residence, Blinken did not respond to questions shouted by reporters about the potential impact of Biden's decision on bilateral ties.

Analysts say that while it could have a chilling effect on Japanese investment into the U.S., any damage to their wider relationship will probably be limited given the two countries' shared security concerns about China.

Business lobbies in both Japan and the U.S. have pushed hard for the merger, backing their arguments up with warnings about the effect on the vital U.S.-Japan relationship.

But it still faced opposition from both Biden and President-elect Donald Trump, who takes office on Jan. 20 and was assiduously courted by Japan in the run up to his re-election.

Ahead of his trip, the State Department said Blinken wanted to build on the momentum of U.S.-Japan-South Korea trilateral cooperation.

In Seoul on Monday, Blinken reaffirmed confidence in South Korea's handling of its political turmoil as investigators there sought to extend a warrant for the arrest of impeached President Yoon Suk Yeol.

Trump's allies have also reassured Seoul and Tokyo he will support continuing efforts to improve ties and advance military, economic and diplomatic cooperation to counter China and North Korea, Reuters reported ahead of the U.S. election.