A North Korean propaganda film has revealed footage of a newly developed cruise missile, according to experts.
The missile is believed to be similar to the Russian KH-35 missile, which came into service in 2003.
Cruise missiles are weapons guided by on-board computers, used to attack specific targets. The majority of the North's known missiles are much larger missiles.
The North is under UN sanctions over its weapons and nuclear programmes.
Pyongyang has carried out three nuclear tests in 2006, 2009 and 2013, and is thought to have enough nuclear material for a small number of bombs.
However, analysts say the North does not appear to have successfully manufactured a nuclear warhead small enough to be carried by its missiles.
ANALYSIS: Jonathan Marcus, diplomatic correspondent, BBC News
Fast, sea-skimming cruise missiles represent a potent threat to modern warships. So the apparent evidence that North Korea might now have its own anti-ship missile is of concern, and not just to the US Navy and North Korea's neighbours.
Pyongyang has established a significant cash and carry business selling its home-built ballistic missiles and there are clearly concerns that North Korea could seek to market a new line in cruise missiles as well.
There's much debate among experts as to just where North Korea might have got its cruise missile, which bears a remarkable resemblance to the Russian Kh-35 Uran. This was developed during the 1980s and 1990s. It can carry a 150kg warhead out to about 130km (80 miles).
A direct export by Moscow would break the UN arms embargo against Pyongyang. There's speculation that maybe the North Koreans obtained their prototype from Myanmar, or via the black market.
North Korea's suspected new cruise missile was revealed for only a split second at the end of the 50-minute propaganda film.
It appeared in between montages of soldiers shouting, tanks firing in unison and leader Kim Jong-un laughing.
From that brief glimpse, some analysts have deduced that the missile is a modified version of the KH-35 anti-ship missile.
North Korea expert Jeffrey Lewis wrote on the 38 North website that the cruise missile would be a "potentially destabilising addition to North Korea's missile arsenal".
It is unclear whether North Korea previously owned any cruise missiles.
South Korean media has already speculated that the cruise missile could pose a potential new threat to the South's navy.