The United States is asking the United Nations Security Council to take action against North Korea for firing two rounds of ballistic missiles.
The US said the launches in the past week were in "clear and calculated violations" of UN sanctions.
A report by the US to the council committee monitoring sanctions against North Korea, which was seen by The Associated Press on Wednesday (local time), asks its members and experts to examine the Scud missile launches and take "appropriate action" in response to the violations of multiple Security Council resolutions.
Under UN sanctions dating back to 2006, North Korea is prohibited from carrying out any launches that use ballistic missile technology. Subsequent UN resolutions require the North to abandon all ballistic missile programmes.
Ballistic missiles can be used to launch nuclear weapons, and the resolutions also demand that North Korea halt nuclear tests and abandon all nuclear weapons and nuclear programmes.
The report said that according to US government information, North Korea launched two Scud short-range ballistic missiles from its southeastern coast on February 27 and two more Scud missiles from the same coast on March 3. It said all four missiles flew in a northeasterly direction and landed in the sea.
"Both the February 27 and March 3 launches clearly used ballistic missile technology and were therefore prohibited," the report said.
The launches appear to be a continuation of North Korea's protest of the ongoing annual military exercises between South Korea and the United States. Pyongyang calls the exercises preparation for an attack, and a test of weapons systems.
The US report noted that when North Korea last launched Scud missiles on July 4, 2009, the Security Council "strongly condemned and expressed grave concern at the launches", saying they violated UN sanctions resolutions "and pose a threat to regional and international security".
The sanctions committee will consider the US report and decide whether to recommend action by the Security Council.
Luxembourg's UN Ambassador Sylvie Lucas, who chairs the sanctions committee, expressed appreciation to the United States for its notification and encouraged US authorities investigating the launches to continue to co-operate with the committee.
North Korea routinely test-fires short-range missiles, and outside analysts said the recent launches weren't expected to raise tensions.
Last spring, North Korea repeatedly threatened to launch a nuclear war following its third nuclear test in February 2013. Recently, North Korea has pushed for improved ties with South Korea and taken conciliatory gestures, including rare reunions of Korean War-divided families last month.
The two Koreas are divided along the world's most heavily fortified border since the 1950-53 Korean War ended with an armistice, not a peace treaty.