The Japanese government on Wednesday ruled out any negative impact from the dismissal of U.S. Secretary of State Rex Tillerson on its cooperation with Washington in dealing with North Korea.

"The Japanese and the U.S. governments have closely communicated with each other through various channels, including between Prime Minister (Shinzo) Abe and President (Donald) Trump. In that sense, we do not anticipate any negative impact," Chief Cabinet Secretary Yoshihide Suga said in a press conference.

The top government spokesman also underlined that Tokyo, Washington and Seoul will maintain their policy to keep putting "maximum pressure" on Pyongyang to prod it to give up its nuclear and missile programs as well as resolve the issue of the North's past abduction of Japanese nationals.

Trump dismissed Tillerson on Tuesday amid rifts over such issues as the Iran nuclear accord and the approach toward North Korea, and appointed Central Intelligence Agency chief Mike Pompeo as his successor.

Foreign Minister Taro Kono also said he does not think the U.S. chief diplomat's exit will have an impact in the run-up to the envisioned U.S.-North Korea summit by May.

"I've heard that President Trump led the decision (to hold the talks). So I believe the mainstream (policy) will be unaffected," Kono told reporters at his ministry.

Last week, Trump accepted North Korean leader Kim Jong Un's proposal to hold a first-ever meeting between incumbent leaders of the two countries in the coming months.

But the Japanese foreign minister said Tillerson's departure was "really regrettable, personally" as the two trusted each other and were able to talk in a candid manner.

Kono, meanwhile, expressed readiness to work with Pompeo, saying, "The United States holds the key to the North Korean crisis. I would like to meet the incoming secretary of state as soon as possible and start exchanging views over the North and other issues."

He had planned to visit Washington later this week to hold talks with Tillerson over the latest developments concerning the North. A source close to him said the minister instructed staff to keep to the schedule and arrange talks with senior U.S. officials.