Ex-CIA chief says working with China is the only option for combating North Korean threat

Since North Korea's apparent first successful launch of an intercontinental ballistic missile on Tuesday, calls for toppling the Kim regime have gained momentum, but former CIA Chief James Woolsey says working with China is still the United States' "only card."

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"Regime change in North Korea is very difficult, and I don't know what leverage we've got," Woolsey said speaking to AOL.com. "It's very hard to figure out how to do that, and Kim Jong-Un doesn't seem like the type of leader that can be persuaded to step down by sweet reason."

Woolsey, who served as CIA director under former President Bill Clinton, says the only viable option to combat the growing threat of North Korea is for the U.S. to work with China, a tactic President Trump seems to have been implementing since taking office.

Click through images of North Korea's missiles:

"I think our only card is China," Woolsey said . "We have to convince China to work with us and to continue its economic pressure and enhance its economic pressure... I think China is the ballgame."

But on Wednesday the president seemed to cast doubt on the possibility of the U.S. and China working together to bring an end to the crisis surrounding North Korea. "Trade between China and North Korea grew almost 40% in the first quarter. So much for China working with us - but we had to give it a try!" Trump tweeted, after months of appearing enthusiastic about working with the country.

As North Korea continues to test weapons, Trump seems to be growing doubtful that working with China will have an impact.

Experts, including the Wall Street Journal editorial board, are also losing faith in a diplomatic solution, with the Wall Street Journal publishing an editorial on Wednesday calling for steps to be made toward removing Kim Jong-Un from power.

"Only a much tougher strategy aimed at toppling the Kim regime, with or without China's help, has a chance of eliminating a threat that puts millions of American lives at risk," wrote the Wall Street Journal on Wednesday.

A timeline of the student's North Korea imprisonment:

Jake Novak, columnist for CNBC, agrees that a more aggressive strategy is needed and that the "clear goal now is regime change, and regime change by either peaceful or at least much less lethal means."

Trump has recently placed even more pressure on China, as Secretary of the Treasury Steven Mnuchin announced last week that the U.S. has imposed sanctions on a Chinese bank for laundering money for North Korea.

But Woolsey says the United States needs to do more to insure North Korea is feeling pressure economically, saying in the end "the most important player in the whole thing is China."