The country's state news agency, KCNA, accused the USA of betraying the spirit of an accord signed by Donald Trump and Kim Jong-un in Singapore previous year.
The North Korean foreign ministry said in a statement that it rejected the United Nations security resolutions against their country, which the US used as reasoning to take control of the ship and demanded a return of the vessel.
Last week the United States justice department accused Pyongyang of violating global sanctions by using the vessel for coal shipments. However, this latest move was "a total denial of the fundamental spirit" of that meeting according to the statement.
'The US must realise the effect of its gangster-like actions. and must return our ship without delay, ' the statement added. The ship, known as the "Wise Honest", had initially been detained by Indonesian officials in April 2018 but has since been impounded by the USA and taken to American Samoa.
North Korea said on Tuesday the seizure of one of its cargo ships by the United States was an illegal act that violated the spirit of a summit between the two countries' leaders, and demanded the return of the vessel without delay.
This is the first time the USA has seized a North Korean ship for breaching sanctions and comes amid worsening relations between the two countries.
Since 2018, North Korea has been engaged in denuclearisation talks with the United States. A second meeting between the two leaders collapsed in February over demands about sanctions relief and nuclear disbarment.
The announcement of the United States seizure of the vessel came as tensions rose over Pyongyang's test launches of short-range missiles last week.
The seizure of the cargo ship, which was announced last week, came at a delicate moment in U.S.
A senior North Korean foreign ministry official on Saturday lashed out at last week's statement by the U.S. State Department that Pyongyang's regime subjected its people to "egregious violations" of human rights including 100,000 in political prison camps.
U.S. Attorney Geoffrey Berman said this is the first time a North Korean cargo ship was seized for violating global sanctions.
USA officials believe North Korea uses the money from coal sales to fund its weapons program.