The United States called the tests a provocation, and the UN Security Council is scheduling an emergency meeting.
But North Korea has remained defiant, with the latest reports indicating it test-fired another missile early on July 5.
The missile tests were not, apparently, a complete success.
U.S. officials said the long-range Taepodong-2 failed just seconds after it took off.
But the launches, coming after weeks of international warnings, sent a powerful message of defiance.
South Korea said the move would deepen its neighbor's international isolation. Japan banned a North Korean ferry from Japanese ports for six months and threatened economic sanctions. And Russia said the tests undermined international efforts to ease nuclear tensions on the Korean peninsula.
Thomas Schieffer, the U.S. ambassador to Japan, said the tests were "a very provocative act" and "very dangerous."
It is impossible to know for sure what the secretive communist state wanted to achieve by these tests.
But they appeared timed to gain as much attention as possible from the United States. They came as America celebrated its July 4 Independence Day holiday, and just hours after the U.S. space shuttle Discovery blasted off from Florida.
Whatever the motive, Australian Prime Minister John Howard said the tests violated the North's own voluntary moratorium that it adopted seven years ago.
"North Korea should be condemned by everybody, as she undoubtedly will be," Howard said.
But North Korea has remained defiant.
Its media made no mention of the launches, though a Foreign Ministry official, Ri Pyong Dok, told reporters that the regime had an undeniable right to test missiles.