President Trump announced early Tuesday that he would allow Japan and South Korea to buy a “substantially increased” amount of sophisticated U.S. military equipment in the wake of the latest threat out of North Korea.

“I am allowing Japan & South Korea to buy a substantially increased amount of highly sophisticated military equipment from the United States,” Trump tweeted Tuesday.

His message comes just one day after he held a call with South Korean President Moon Jae-in to discuss North Korea’s claimed test of a hydrogen bomb. According to the White House, the two leaders agreed to “maximize pressure” on North Korea by using “all means at their disposal.”

On the call Monday, the White House said, Trump provided his “conceptual approval” for South Korea’s purchase of “many billions of dollars’” worth of U.S. military weapons and equipment. Though details have yet to be released, the leaders hoped to signal that the countries were working together to boost a defensive response to Kim Jong Un’s threat.

South Korea’s presidential office also said in a statement that Trump and South Korea's president agreed to remove the limit on the payload of South Korean missiles as part of the countries’ response to the North’s move.

The U.S. currently has approximately 28,000 troops in South Korea, and hundreds of thousands of American citizens in the capital.

The president also spoke with Japan’s Prime Minister Shinzo Abe on Sunday to discuss the rogue regime’s Sept. 3 bomb test.

“President Trump reaffirmed the commitment of the United States to defending our homeland, territories, and allies using the full range of diplomatic, conventional, and nuclear capabilities at our disposal,” the White House said in a statement Sunday after the call.

But according to a Japanese magazine, Nikkei Asian Review, Japan is reportedly planning for possible mass evacuations of its citizens in South Korea as tensions rise with the rogue regime.

And South Korea had held two live-fire exercises in an effort to show its military capability. The exercises were in an effort to “strongly warn” Pyongyang, according to South Korean officials.

But U.S. Ambassador to the United Nations Nikki Haley said that “the time for half measures…is over.”

“We cannot kick this can down the road any longer,” Haley said Monday at the U.N. headquarters in New York City. “Enough is enough. War is never something the United States wants…But our country’s patience is not unlimited.”

Other members in the Trump administration, like Secretary of Defense Jim Mattis, warned North Korea that any threats to the U.S. or its allies would be met with an “effective and overwhelming” military response.

The Associated Press contributed to this report.