'No risk-free options' on North Korea's nuclear and missile programs : US Army Chief of Staff General Mark Milley

General Mark Milley, Chief of Staff of the US Army, speaks at the National Press Club, July 27, 2017 in Washington, DC. (AFP photo)

US Army Chief of Staff General Mark Milley has warned that there are "no risk-free options" in solving the challenge of North Korea's nuclear and missile programs.

Milley also said Monday that North Korea gaining possession of an intercontinental ballistic missile with a nuclear warhead capable of striking the US would be unacceptable.

"There are no good, easy, you know, risk-free options here. This is extraordinarily difficult, extraordinarily dangerous. No one should underestimate it," Milley told reporters during a news conference on the sidelines of the Association of the US Army's annual meeting in Washington.

"A full-blown war on the Korean Peninsula will be horrific by any stretch of the imagination. No one has any doubts about that," he added.

And while Milley said that a full-scale military conflict on the Korean Peninsula would be "horrible," he also warned that there is not an "indefinite amount of time" to solve the crisis.

"It would be horrible, there's no question about it, but so would an intercontinental ballistic missile striking Los Angeles or New York City. That would be equally horrible," he said.

The general’s comments come just hours after US President Donald Trump issued a tweet which condemned attempts by previous US administrations to solve the North Korean issue through negotiations with Pyongyang.

"Our country has been unsuccessfully dealing with North Korea for 25 years, giving billions of dollars & getting nothing. Policy didn't work," Trump wrote.

On Monday, US Defense Secretary James Mattis once again reiterated that diplomacy along with international economic sanctions against North Korea would remain Washington’s leading strategy towards Pyongyang.

But Mattis added that the Pentagon would continue to prepare military options if diplomacy fails. "We've got to be ready to ensure that there are military options that our President can employ if needed," he said.

North Korea has conducted several nuclear tests and missile test-launches in response to US threats against the country.

Pyongyang says it will not give up on its nuclear deterrence unless Washington ends its hostile policy toward the country and dissolves the US-led UN command in South Korea. Thousands of US soldiers are stationed in South Korea and Japan.