Tensions between the US and North Koreawere raised after Pyongyang launched a missile on Sunday morning. The test appeared to fail, with a White House foreign policy adviser saying it was a medium range missile that exploded four to five seconds after it was launched from an eastern port city.
On an unannounced visit to the border between South Korea and its northern neighbour on Monday, Mr Pence made comments suggesting the US would go to extreme measures to force Pyongyang to end its nuclear weapons programme.
He said: “We want to see North Korea abandon its reckless path of the development of nuclear weapons, and also its continual use and testing of ballistic missiles is unacceptable.”
His comments come after US Secretary of State Rex Tillerson visited the border area last month, saying that pre-emptive military action was “on the table”.
Mr Pence called on China, which has long been considered North Korea only significant strategic ally, to use its “extraordinary levers” to persuade the isolationist state to give up its nuclear arms.
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In Washington, Mr Trump was asked if he had a message for North Korean leader Kim Jong-un. He replied: “Gotta behave.”
At a news conference at the UN on Monday, North Korean representative Ambassador Kim In-ryong, criticised recent US missile strikes in Syria, which targeted a military base after a suspected chemical attack.
He said the US was "disturbing global peace and stability and insisting on [a] gangster-like logic".
North Korean leader Kim Jong-un has overseen three nuclear tests and a series of missile and nuclear launches since assuming control after the death of his father, Kim Jong-il in 2011.
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