Biden rolled out the red carpet for Kishida with a lavish dinner, plus music by US singer Paul Simon, as he underscored Japan's importance as a key ally against Beijing in the Asia-Pacific region.

The two leaders even agreed that a Japanese astronaut will be the first non-American to walk on the Moon, as they sought to take the alliance to new heights.

"This is the most significant upgrade in our alliance since it was first established," Biden, 81, told a press conference with Kishida in the White House Rose Garden.

The two leaders unveiled plans to restructure the US military command in Japan, the biggest such change since the 1960s. The move is aimed at making US and Japanese forces more nimble in the event of threats, such as a Chinese invasion of Taiwan.

The United States, Japan and Australia would also launch a joint air defense network, while Britain would take part in military exercises with Washington and Tokyo.

'Peace and stability'

For his part, Kishida hailed the Japan-US alliance as crucial for upholding peace and democracy in the region, where China has been increasingly assertive.

He called for "peace and stability" across the Taiwan Strait -- but also took aim at Russia for its invasion of Ukraine.

"Ukraine today, maybe East Asia tomorrow," he said.

Biden insisted that the military upgrade in China's backyard was "purely defensive" but has made no bones about his desire to create alliances to counter China.

On Thursday, he will host the first trilateral summit between Japan, the Philippines and the United States, to support Manila amid tensions with China in the South China Sea.

US officials said the broader boost in ties was also aimed at reassuring allies of long-term support even if Donald Trump beats Biden in November's US presidential election.

The pomp-filled state visit for Kishida was however also meant to underscore the broader cultural and economic relations between two allied nations who were at war 80 years ago.

Biden announced that a Japanese person will be the first non-American to walk on the Moon, flying on a US mission due to take place in a few years' time.

The leaders also announced deals for technology, including artificial intelligence and the economy.

‘Boldly go’

The rest of the day was dedicated to extravagant hosting of 66-year-old Kishida and his wife Yuko.

Guests at the White House state dinner included actor Robert DeNiro, Amazon boss Jeff Bezos, Apple chief Tim Cook, and former president Bill Clinton and ex-secretary of state Hillary Clinton, the White House said.

Biden led the room in a toast "to our alliance, to our friendship."

In his toast Kishida quoted lines from the cult 1960s US television show Star Trek, whose title sequence referred to space as the "final frontier" and described a mission to "boldly go where no man has gone before."

"I would like to propose a toast to our voyage to the frontier of the US-Japan relationship with these words -- boldly go!" said Kishida, also noting the Japanese heritage of star George Takei.

Sitting at tables decorated by fans and cherry blossom branches, guests tucked into house-cured salmon, dry-aged rib eye with wasabi sauce, and salted caramel pistachio cake with cherry ice cream.

After dinner, "Bridge Over Troubled Water" star Simon was due to perform a selection of songs.

Kishida is the first Japanese leader to get a US state visit since Shinzo Abe in 2015, and only the fifth world leader to receive one since Biden took office in 2021.

Four of those have been Asian leaders, reflecting Biden's strategic priorities even as he wrestles with wars in Ukraine and Gaza.

Staunchly pacifist for decades, Japan has in recent years made "some of the most significant, momentous changes" since World War II, US ambassador to Japan Rahm Emanuel said ahead of the visit.