Toughest US Sanctions On N Korea sanctions

The measures will target more than 50 ships and maritime transport companies.

Mr Trump said in sections of a speech released in advance said that he is announcing the launching of the largest-ever set of new sanctions on the North Korean regime," Mr Trump said in sections of a speech released in advance.

North Korea is already under a range of international and US sanctions over its nuclear programme and missile tests.

"The treasury department will soon be taking new action to further cut off sources of revenue and fuel that the regime uses to fund its nuclear programme and sustain its military by targeting 56 vessels, shipping companies, and trade businesses that are assisting North Korea in evading sanctions," Mr Trump says.

Sixteen, mainly shipping companies, are based in North Korea, but five are registered in Hong Kong, two on the Chinese mainland, two in Taiwan, one in Panama and one in Singapore. 

Twenty-eight ships are on the list, again mostly North Korean, but two are Panama-flagged, one from the Comoros and one Tanzania-flagged.

The US has been building sanctions against the regime since 2008 and the latest restrictions could come on top of sanctions announced in November - directed at North Korean shipping operations, as well as Chinese companies trading with Pyongyang. 

The United Nations followed that up in December with a raft of sanctions, backed by all 15 members of the Security Council, which included measures to cut North Korea's petrol imports by up to 90%.

North Korea's response to sanctions

• 30 November 2016: UN sanctions targeted North Korea's valuable coal trade with China, slashing exports by about 60% under a new sales cap. Exports of copper, nickel, silver, zinc and the sale of statues were also banned
• What happened next? On 14 May 2017, North Korea tested what it said was a "newly developed ballistic rocket" capable of carrying a large nuclear warhead
• 2 June 2017: UN imposed a travel ban and asset freeze on four entities and 14 officials, including the head of North Korea's overseas spying operations
• What happened next? On 4 July, North Korea claimed it had carried out its first successful test of an intercontinental ballistic missile (ICBM)
• 6 August 2017: UN banned North Korean exports of coal, ore and other raw materials and limited investments in the country, costing Pyongyang an estimated $1bn - about a third of its export economy
• What happened next? On 3 September, North Korea said it had tested a hydrogen bomb that could be miniaturised and loaded on a long-range missile.