FORMER US president Barack Obama undertook a series of cyberattacks against North Korea's missile program, the New York Times is reporting.
Obama warned his successor Donald Trump that the North Korean nuclear program would be his biggest international challenge, and Trump's advisers are now weighing options that include continuing the cyberattacks.
Obama began the attacks in 2014 after concluding antimissile systems were not enough to protect the United States and chose instead to target missiles before test launches, the report said. Details of the program were not released at the request of national security officials, the newspaper said.
The attacks were said to work, with a number of missiles malfunctioning on takeoff of early in flight.
After the US implemented the strategy, several missile launches failed or veered off course.
The UN tightened sanctions on North Korea in November, two months after it carried out its fifth nuclear test, in a bid to prevent it from developing nuclear weapons.
The United States still cannot effectively counter North Korea's nuclear and missile programs, the The New York Times reported following a months-long investigation, based on interviews with officials in the Obama and Donald Trump administrations as well as "a review of extensive but obscure public records."
North Korea's threats remain so dangerous that when Obama left office he warned Trump that this would likely be the most urgent problem he'd face, the Times said.
Three years ago Obama ordered the Pentagon to increase cyber and electronic attacks against North Korea to try to sabotage its missiles before launch or just as they lift off, the report said.
The program appeared to be successful, as several of the North's rockets and missiles failed soon after launch.
Advocates of the US program claimed success, believing that they had delayed for years North Korea's ability to mount a nuclear weapon on an intercontinental ballistic missile (ICBM) and threaten a US city.
Skeptics however said the failures could have resulted from shoddy manufacturing, disgruntled insiders and simple incompetence.
Kim Jong-un's isolated regime has continued to thumb its nose at the world with a series of missile launches over the years.
It has conducted three successful medium-range rocket launches in the past eight months and two nuclear tests in 2016 in its quest to build an ICBM that could reach the United States.
North Korea is barred under UN resolutions from any use of ballistic missile technology.
The UN Security Council has imposed six sets of sanctions since Pyongyang first tested an atomic device in 2006.
Kim boasted in January that Pyongyang was in the "final stages" of developing an ICBM in an apparent attempt to pressure the incoming US president. Trump shot back on Twitter, saying, "It won't happen."
On February 12 North Korea fired what appeared to be a modified intermediate-range Musudan missile, which landed in the ocean.
The Musudan has a range of 2500 to 4000km, meaning it could threaten both Japan and US bases on Guam.
Japanese Prime Minister Shinzo Abe called the test "absolutely intolerable."
Days later, US Secretary of State Rex Tillerson pledged that Washington would use the full range of its arsenal, including nuclear weapons, to defend allies Japan and South
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