US President Donald Trump has said that time is "not of the essence" in handling North Korea, amid concerns that renewed tensions over a planned South Korea-US military exercise could hamper the resumption of working-level nuclear talks with the regime.

Trump made the remarks during a Cabinet meeting Tuesday where he also boasted of "tremendous progress" in his diplomacy with Pyongyang and predicted that "good things" will ultimately happen.

The remarks came hours after North's foreign ministry criticized the allies' exercise set for next month and hinted that it could boycott working-level talks that Trump and North Korean leader Kim Jong-un agreed to restart during their impromptu encounter at the Demilitarized Zone last month.

"We've (made) tremendous progress. People don't like saying that. The progress is great communication. Before, we had no communication. There was zero -- zero communication," Trump said according to the transcript released by the White House.

"And, again, time is not of the essence, but I think good things will ultimately happen," he added.

Trump pointed out that sanctions are still on in cooperation with countries bordering the North, while listing a series of achievements that his administration has made in its diplomacy with the communist regime.

"In the meantime, as I say, we got our hostages back. We got the remains back, and they continue to come," he said. "We have the sanctions on in full. We're working with China. We're working with Russia on the border."

He also reiterated that he is "in absolutely no hurry."

"But at some point, I think we can probably do something that would be very good for them and very good for everybody and for the world," he said.

In addition, Trump touched on his DMZ meeting with Kim.

"We had a great meeting," he said. "It was pretty wild. Very good communication. We'll see what happens." (Yonhap)