Myanmar's military regime suggested six years ago it might "go nuclear" to gain the attention of the United States, according to a senior Indian diplomat quoted in a leaked US cable.

The memo from the US embassy in New Delhi also quoted the diplomat as saying Myanmar democracy icon Aung San Suu Kyi's "day has come and gone" and that only engagement with the junta could bring meaningful change.

Sanctions had isolated Myanmar, also known as Burma, and had not encouraged democratic reforms, Mitra Vasisht, joint secretary at India's Ministry of External Affairs, said after a visit by military leader Than Shwe.

"Burma is so isolated that members of Than Shwe's delegation wondered whether they would have to 'go nuclear' to get US attention, she remarked, noting the comparison to Pakistan," according to the November 2004 memo, obtained by British daily The Guardian from the WikiLeaks website.

Another leaked cable from the US embassy in Yangon, released by Wikileaks earlier this month, showed that Washington has suspected for years that Myanmar has a secret nuclear programme, possibly supported by North Korea.

One memo, dated August 2004, quoted an unidentified source as saying he saw about 300 North Koreans working at an underground site in Myanmar.

Myanmar's junta has dismissed reports of its nuclear intentions and brushed aside Western concerns about possible cooperation with North Korea.

The regime last month held a widely criticised election seen as prolonging military rule, with Suu Kyi locked up during the vote.

The Nobel Peace Prize winner has spent most of the past 20 years in detention but was freed from her latest seven-year stretch of house arrest on November 13.

Her National League for Democracy party was disbanded for boycotting the country's first election in 20 years in response to rules that seemed designed to bar her from taking part.

The US memo from New Delhi also said Myanmar's military ruler travelled with the wives of two other powerful generals, Thura Shwe Man and Soe Win, "who she (Vasisht) mused may have been used as 'hostages' to ensure tranquillity among the generals in Rangoon (Yangon) during Than Shwe's absence".