TOKYO — North Korea launched two missiles Thursday, marking its 12th test since May, in an apparent effort to pressure the United States to return to denuclearization talks with a better offer.

The missile test comes four days after North Korea warned that it was losing patience with the United States and its “hostile policy” and restated its end-of-year deadline for Washington to change its approach. 

The “short-range projectiles” were launched from the province immediately north of the capital, Pyongyang, South Korea’s Joint Chiefs of Staff said in a statement, reaching an altitude of 55 miles and flying about 230 miles into the sea off the east coast.

“This type of act from North Korea does not help efforts to alleviate tensions on the Korean Peninsula, and we urge North Korea to stop immediately,” they said. South Korea’s National Security Council expressed its “strong concern.”

Japanese Prime Minister Shinzo Abe said the test involved ballistic missiles, and strongly condemned it as a threat to the peace and security of his country and region.

North Korea's top negotiator said nuclear talks with the U.S. broke down because the Washington delegation would not "give up their old viewpoint and attitude." (Reuters)

The missiles were fired a day after North Korean leader Kim Jong Un sent a condolence letter to his South Korean counterpart, Moon Jae-in, after the death of his mother. 

Kim expressed his “deep condolences” and offered a “consoling message to President Moon” in the letter delivered via the border village of Panmunjom late Wednesday, South Korea said Thursday. 

But the missile tests only underlined how badly relations have deteriorated this year between North and South Korea, and with the United States. 

Talks between North Korean and U.S. officials broke down in Stockholm earlier this month. After an eight-month stalemate, the United States had hoped to breathe new life into the negotiations, but North Korea walked away, calling the discussions “sickening.” 

Then, two weeks ago, Kim was shown riding a white horse in the snow on the sacred Mount Paektu, with state media saying he was planning a “great operation.” 

Last week, Kim ordered the removal of South Korean facilities at a shuttered joint tourist project, and he has since rebuffed Seoul’s attempt to hold talks on the issue.

On Sunday, Pyongyang repeated its frustration with what it calls a “crafty and vicious” attempt by the United States to isolate and stifle the country through sanctions. The statement said the United States is seriously mistaken if it thinks it can keep the situation quiet through the end of the year by exploiting the “close personal relations” between President Trump and Kim.

More fiery rhetoric emerged from state media on Tuesday, this time attributed to leading official Choe Ryong Hae at an earlier speech to a summit of the Nonaligned Movement in Azerbaijan.

“Now the situation on the Korean Peninsula is at a critical crossroads of either moving toward a durable peace along with the trend of detente or facing again a touch-and-go crisis,” Choe said.

The missile test may have been partly aimed at underlining the point.

“It is consistent with hardening signals from state media since the breakdown of the Stockholm talks and Kim’s climb up Mount Paektu,” said Rachel Minyoung Lee, a senior analyst at NK News, a Seoul-based website specializing in North Korea news and analysis. 

Some experts think the fire and fury coming from Pyongyang is an attempt to drive a hard bargain with Trump, in the hope that he will offer North Korea a favorable deal in return for not disrupting his reelection campaign with more serious long-range-missile tests.

Min Joo Kim in Seoul contributed to this report.