SEOUL (REUTERS) - North Korea fired two short-range ballistic missiles early on Wednesday, the South Korean military said, only days after it launched two similar missiles intended to pressure South Korea and the United States to stop upcoming military drills.

The latest launches were from the Wonsan area on North Korea's east coast, the same area from where missiles were fired last week, South Korea's Joint Chiefs of Staff (JCS) said in a statement.

It said it was monitoring in case of more launches. The JCS said later the North had fired ballistic missiles that flew about 250 km (155 miles) and that they appeared to be similar to those launched last week.

Wednesday's launch follows ballistic missile firings on July 25, North Korea' first missile tests since leader Kim Jong Un and US President Donald Trump met on June 30 and agreed to revive stalled denuclearisation talks.

"North Korea's actions do not help ease military tensions, nor do they help keep the momentum for talks that are under way," South Korean Foreign Minister Kang Kyung-wha told reporters. She urged North Korea to halt the missile launches.

The White House, the Pentagon and the US State Department did not respond immediately to requests for comment.

Colonel Lee Peters, a spokesman for US military forces in South Korea, said: "We are aware of reports of a missile launch from North Korea and we will continue to monitor the situation."

Prime Minister Shinzo Abe said that there was no impact on Japan's security following North Korea's latest launch of short-range ballistic missiles and that Japan was working with its allies over the situation in the region.

"We will continue to closely cooperate with the United States and others," Mr Abe told reporters.

The Japanese Ministry of Defence said no ballistic missiles had reached Japan's territory or its exclusive economic zone.

Japanese Defence Minister Takeshi Iwaya said any ballistic missile launch by North Korea would violate United Nations resolutions, Japan's Kyodo news agency reported. He added that the ministry would analyse North Korea's intentions and objectives.

Despite the latest missile launch, Japan would continue to seek a summit with North Korea, without conditions, said Chief Cabinet Secretary Yoshihide Suga said on Wednesday.

A South Korean defence official said initial estimates showed the missiles fired on Wednesday could be similar to those last week, although they were still working to confirm details.

Dubbed the KN-23, those missiles are designed to evade missile defence systems by being easier to hide, launch, and manoeuvre in flight, experts said. Kim described the two KN-23s launched last week as having a"low-altitude gliding and leaping flight" pattern that would make them hard to intercept.

Analysts said the range and altitude of Wednesday's flights could indicate a test of those capabilities.

North Korea test-fired two new short-range ballistic missiles last Thursday, its first missile tests since leader Kim Jong Un and US President Donald Trump met in late June and agreed to revive stalled denuclearisation talks.

Both Mr Trump and US Secretary of State Mike Pompeo played down last week's launches and Mr Pompeo has continued to express hope for a diplomatic way forward with North Korea.

Since the June 30 meeting in the Demilitarised Zone (DMZ) between the two Koreas, Pyongyang has accused Washington of breaking a promise by planning to hold joint military exercises with South Korea in August and warned that these could derail any dialogue.

North Korea has also warned of a possible end to its freeze on nuclear and long-range missile tests in place since 2017, which Mr Trump has repeatedly upheld as evidence of the success of his engagement with Mr Kim.

A February summit in Vietnam between Mr Trump and Mr Kim collapsed after the two sides failed to reconcile differences between Washington's demands for Pyongyang's complete denuclearisation and North Korean demands for sanctions relief.

A North Korean official told a White House National Security Council counterpart last week that working-level talks would start very soon, a senior US administration official said earlier on Tuesday. The NSC official, who was in Asia for unrelated talks, travelled to the DMZ to deliver photographs commemorating the June 30 summit, the senior administration official told reporters.

Mr Trump reiterated to reporters at the White House on Tuesday that he had a good relationship with Mr Kim, but added: "We'll see what happens. I can't tell you what's going to happen."

Mr Pompeo said on Monday that he hoped working-level talks to revive denuclearisation talks could occur "very soon", but emphasised that a follow-up leaders' summit was not planned.

Mr Pompeo and North Korean Foreign Minister Ri Yong Ho had been expected to meet on the sidelines of a South-east Asia security forum in Bangkok this week, but Mr Ri cancelled his trip to the conference, a diplomatic source said.

On Tuesday, Mr Pompeo said he did not anticipate that the North Koreans would be in Bangkok, but if they were he would look forward to a chance to meet Mr Ri. "We'll see if they are there, and if they are, I'm confident we will meet."

Mr Harry Kazianis, of Washington's Centre for the National Interest think tank, said the latest launches were a clear attempt by North Korea to put pressure on Washington. "For now, it seems any working-level talks between America and North Korea are on hold until the fall, as the Kim regime won't immediately spring back to diplomacy after this round of tests," he said.

Other analysts have said that North Korea will have been emboldened to press more aggressively for US concessions by Trump's apparent eagerness to hold up his engagement with North Korea as a foreign policy success ahead of his 2020 re-election bid.