The launch has been detected by the South Korean military but there are no further details on the matter, the news agency reported.
Yonhap later reported, citing the South Korean military, that the launch of Pyongyang's unidentified ballistic missile appears to have failed.
Japanese broadcaster NHK reported, citing a government source, that the North's missile appears to have landed outside Japan's exclusive economic zone.
The South Korean Joint Chiefs of Staff confirmed on Wednesday that Pyongyang's launch appears to have failed.
"Today, on June 26, at around 5:30 a.m. [local time, 20:30 GMT on June 25], North Korea launched an unspecified ballistic missile from the area around Pyongyang toward the East Sea [the Sea of Japan], but presumably unsuccessfully. South Korean and US agencies continue additional analysis," the South's military said in a statement.
Yonhap cited a military source as saying that Pyongyang appears to have test-fired a hypersonic missile, but the test is believed to have failed since the missile flew about 250 kilometers (155 miles).
Russian officials repeatedly stressed that US and its allies bear responsibility for worsening situation on the Korean Peninsula, while Pyongyang has no choice but to bolster its military capabilities in order to deter adversaries.