It blew up nearly immediately.
The US would work with China to reduce tensions, Mr Mattis added. He spoke after heated rhetoric from both sides.
(File) Trump interacts with Xi at Mar-a-Lago state in Palm Beach, Florida, US, on April 6, 2017.
"We are conducting a practical and more intensive exercise than ever", South Korean pilot Colonel Lee Bum-chul told reporters.
Gobierno nacional decreta 100% cobertura de salud en Miranda
Anunció que ahora viene la etapa de perfeccionamiento de la Misión Barrio Adentro, que estará enlazada al carnet de la Patria. Palacio de Miraflores, Caracas .
The U.S.is also taking action to deter North Korea.
The US appeared to be following the same policy in Asia, declining to get too involved in conflicts such as in the South China Sea.
U.S. President Donald Trump has taken a hard line with North Korean leader Kim Jong Un, who has rebuffed admonitions from sole major ally China and proceeded with nuclear and missile programmes in defiance of U.N. Security Council sanctions.
Asked by CBS News if she considers ballistic missile tests to be a provocation, she said the USA evaluates North Korean action based on whether the country "violates Security Council resolutions, so they definitely have done that".
"It is a situation where a lot of exercise equipment is amassed in North Korea and also a lot of strategic assets are situated on the Korean peninsula because of the South Korea-U.S. military drills", Lee told a briefing.
US Ambassador Nikki Haley separately stressed that the onus was on North Korea to prevent an escalation.
The failed launch came a day after the 105th anniversary of the birth of North Korea's founding father, Kim Il Sung, the current leader's grandfather.
BOMBSHELL: Rep. Jason Chaffetz Says He's Not Running for Re-Election
Trump won the Beehive State in 2016 but voters in the largely Mormon state were less than thrilled with his brand of conservatism. And like many Republican members of Congress, Chaffetz faced a fiery crowd in a town hall in February.
The term "reckless" is one the North Koreans have used to describe continuing large-scale US and South Korean military exercises, which the North calls a dress rehearsal for an invasion.
But John Schilling from the 38 North monitoring group said the failure was indicative of the test of a new and hitherto unknown system being developed by Kim Jong-Un's regime.
Next week, US Secretary of State Rex Tillerson will chair a minister-level meeting on the North Korean issue at the UN. We've said it as clearly as we can possibly say it. What's behind the North's latest nuclear bluster?
And what about other world powers?
China's Foreign Ministry said on Wednesday it is seriously concerned by North Korea's promise of further missile tests and warning of war.
The US defence officials said that the defence actions will involve test-firing a standard missile off a Navy ship in May.
Ontario, Canada brings in foreign housing tax to cool market
The province included a number of exemptions to the tax that will make it relatively ineffective at actually cooling demand. Home Capital's stock dropped 19 percent to C$18.10 at 1:56 p.m.in NY , the biggest decline in nearly two years.