President Donald Trump called on U.S. allies, including Japan, to assist in securing the Strait of Hormuz. Trump compared the U.S. military's attack on Iran to the attack on Pearl Harbor during the G7 summit, prompting intervention by other heads of state. According to krcrtv.com, Trump said he and his administration did not warn Japan or other allies ahead of the initial attack in Iran on February 28 because they wanted an element of surprise. Japanese Prime Minister Sanae Takaichi denied that the Trump administration officially requested Japanese warships for the conflict.

Takaichi held a Japan-U.S. Summit Meeting with Trump at the White House on March 19, 2026, followed by a dinner reception hosted by Trump. The summit began with a warm embrace and continued in a harmonious atmosphere, ending 'without incident,' according to nippon.com. Trump praised Takaichi as a 'very popular, powerful woman, and [a] great woman' and commended her for the Liberal Democratic Party’s overwhelming victory in the February 8 House of Representatives contest, calling it a 'tremendous election in a record-setting fashion.' Takaichi expressed appreciation for Trump’s commitment to the Japan-U.S. alliance and stated she would like to deepen discussions to make both nations strong and prosperous.

Takaichi told Trump that Japan is opposed to Iran's development of a nuclear weapon and offered promises to support U.S. efforts to stabilize energy markets and secure supply chains. She also told Trump it is 'only you, Donald, who can achieve peace across the world,' according to thediplomat.com. The summit produced a substantial package of economic deliverables, including record investment announcements, a new Critical Minerals Action Plan, and advancements in technology and defense collaboration, as reported by uschamber.com.