Singapore has suspended trade relations with North Korea, the latest of Pyongyang's major trade partners to cut commercial ties under toughening UN sanctions over its weapons programme, a customs notice obtained on Thursday showed.

The move comes about two months after the United States imposed North Korea-related sanctions on a number of firms and individuals, including two entities based in Singapore.

"Singapore will prohibit all commercially traded goods from, or to, the Democratic People's Republic of Korea (DPRK)," the city-state's customs said in the notice sent to traders and declaring agents last Tuesday, referring to the country by its official name.

The suspension would take effect from November 8, Fauziah A. Sani, head of trade strategy and security for the director-general of customs, said in the notice.

Repeated breach of the new prohibitions is punishable by a fine of up to S$200,000 ($147,340.50) or four times the value of the goods traded, imprisonment of up to three years, or both, it added.

Singapore is North Korea's seventh largest trading partner. The Philippines, Pyongyang's fifth biggest trading partner, suspended trade with North Korea in September to comply with a UN resolution.

Tension on the Korean peninsula has escalated as North Korea's young leader, Kim Jong Un, has stepped up the development of weapons in defiance of UN sanctions.

North Korea has tested a series of missiles this year, including one that flew over Japan, and conducted its sixth and biggest nuclear test in September.

Pyongyang maintains a diplomatic presence in Singapore, with an embassy in its financial district.

In September, Singapore issued a travel advisory urging citizens to avoid all non-essential travel to North Korea, where it does not have diplomatic representation.

In an interview with National Public Radio in May, Singapore's minister of foreign affairs, Vivian Balakrishnan, had said the country was not ready to cut all diplomatic ties with North Korea.

In January last year, Singapore-based Chinpo Shipping Company (Private) Ltd was fined S$180,000 for facilitating a shipment of arms to North Korea in violation of UN sanctions. (http://reut.rs/2ARbm14) ($1 = 1.3574 Singapore dollars)