The Trump administration is seeking US$4bn in emergency spending to pay for urgent missile defence improvements to counter the nuclear threat from North Korea.
The request delivered to Congress today said the cash "supports additional efforts to detect, defeat and defend against any North Korean use of ballistic missiles against the United States, its deployed forces, allies or partners".
It came as President Donald Trump raised the pressure on North Korea by refusing to rule out military action and declaring that the US "will not stand" for Pyongyang menacing the US or its Asian allies.
That includes current and projected threats to the US homeland, Guam, South Korea and Japan.
Portions of the money would be used for the construction of an additional ground-based interceptor field at Fort Greely, Alaska, the initial procurement of 20 new ground-based interceptors, ship-based missiles, and interceptors for the Terminal High-Altitude Area Defence, or THAAD, a US mobile anti-missile system.
Mr Trump, on the first stop of a lengthy Asia tour, denounced North Korea as "a threat to the civilised world", and urged dictator Kim Jong Un to cease testing weapons like the missiles he has fired over Japanese territory in recent weeks.
Though he stood in one of the Asian capitals in range of North Korea's missiles, Mr Trump did not modulate his fiery language, saying Pyongyang endangers "international peace and stability".
"Some people say my rhetoric is very strong but look what has happened with very weak rhetoric in the last 25 years," said Mr Trump, who stood with Japanese prime minister Shinzo Abe at a news conference in Tokyo.
Mr Abe, who has taken a more hawkish view on North Korea than some of his predecessors, agreed with Mr Trump's assessment that "all options are on the table" when dealing with Kim and announced new sanctions against several dozen North Korean individuals.
Mr Trump and Mr Abe have struck up a friendship in meetings, phone calls and on the golf course, a friendship that was on display at a Monday evening banquet that was the final event of Mr Trump's visit.
Mr Abe called Mr Trump his "dear friend" and hailed the benefits of what he called "golf diplomacy".
The two men acknowledge the threat posed by the North, standing with families of Japanese citizens snatched by Pyongyang's agents.
Mr Trump and first lady Melania Trump stood with nearly two dozen relatives, some of whom held photos of the missing.
Seeking to increase pressure on Kim, Mr Trump pledged to work to return the missing to their families, saying: "It's a very, very sad number of stories that we've heard."
North Korea has acknowledged apprehending 13 Japanese in the 1970s and 1980s, but claims they all died or have been released.
Mr Trump has delivered harsh denunciations of Kim, belittling him as "Little Rocket Man", but suggested it would be "a tremendous signal" if North Korea returned the captives.