The July 2009 memo from the US embassy in Yangon said that Myanmar had exported about 20,000 tons of rice to North Korea through military-owned Myanmar Economic Holdings Ltd.
According to a well-placed business source, Myanmar "has been exporting rice and other agricultural commodities to North Korea for over five years in exchange for arms," added the cable, which referred to "conventional weapons".
US diplomatic memos released last year by WikiLeaks said Washington has also suspected for years that Myanmar ran a secret nuclear programme supported by Pyongyang.
A UN report published in November said North Korea was supplying banned nuclear and ballistic equipment to Myanmar, along with Iran and Syria.
Myanmar has dismissed reports of its nuclear intentions and brushed aside Western concerns about possible cooperation with North Korea.
A civilian administration has been nominally in charge of Myanmar since March, following a controversial election last year, but its ranks are dominated by former generals.
Published 05 September 2011, 08:50 IST