GOP lawmakers: Trump's 'strong stand' on North Korea 'starting to work'

President Donald Trump's planned meeting with North Korean dictator Kim Jong Un was met with cheers from many Republican lawmakers -- but some skepticism from others.  

South Korea's national security director Chung Eui-yong said the two world leaders agreed to meet by May. Trump tweeted: “Great progress being made but sanctions will remain until an agreement is reached. Meeting being planned!”

U.S. Sen. Lindsey Graham, R-S.C., praised the president’s efforts to denuclearize North Korea, saying that it “gives us the best hope” to “peacefully” resolve escalating tensions.

While Graham acknowledged North Korea’s past as being “all talk and no action,” he warned Kim directly that “the worst possible thing you can do is meet with President Trump in person and try to play him.”

He added, “If you do that, it will be the end of you – and your regime.”

U.S. Rep. Ed Royce, R-Calif., chairman of the House Foreign Affairs Committee, also said the invitation showed that sanctions on North Korea were “starting to work.”

U.S. Sen. Bob Corker, R-Tenn., chairman of the Senate Foreign Relations Committee, also praised the sanctions implemented by Congress, saying that they “are having a real effect.”

However, some members of the committee remained skeptical.

U.S. Sen. Cory Gardner, R-Colo., said the “price of admission” for Trump and Kim meeting must be “complete, verifiable, and irreversible denuclearization of the Korean Peninsula.”

U.S. Sen. Ed Markey, D-Mass., also said that the invitation was the “beginning of a long diplomatic process” and that Trump needed to avoid “unscripted” remarks that could derail it.

Evan S. Medeiros, a former adviser in the Obama administration, warned that Kim “played” South Korean President Moon Jae-in and “is now playing Trump.”

Medeiros added, “Kim will never give up his nukes.”

The White House confirmed the Trump accepted the invitation but did not reveal and details surrounding when or where a meeting might happen.

Fox News’ Mike Emanuel, Jason Donner and the Associated Press contributed to this report.