Prime Minister John Howard said today he would ask for clemency for Melbourne man Nguyen Tuong Van who is facing the death penalty in Singapore for heroin trafficking.

Mr Howard said he would raise the Australian's case with Singaporean Prime Minister Lee Hsien Loong when they met later today.

Last October, Nguyen, 24, of Mulgrave in Melbourne's south-east, lost an appeal against his conviction and mandatory death sentence for drug trafficking.

"There are compassionate circumstances in that particular case and I'll be putting those compassionate circumstances to the prime minister, yes," Mr Howard told reporters in Singapore.

He said Nguyen cooperated with authorities and was trying to raise money to help a family member.

"He has cooperated with the authorities and he was, although engaged in a criminal act as found by the courts of Singapore, he was endeavouring to secure financial resources to help a family member," Mr Howard said.

"And I'll be putting those issues and other matters in the hope that they will be taken into account by the president of Singapore in the final decision that he must make in relation to whether or not the death penalty is carried out."

Asked if the execution of Nguyen would affect bilateral relations between Australia and Singapore, Mr Howard replied: "Look, I think we have to keep a balance here.

"I believe there's a very good case for clemency but people must understand that the laws of Singapore are well known and I think we'll leave it at that."

- AAP

SINGAPOREAN Prime Minister Lee Hsien Loong promised that his cabinet would consider a condemned Australian man's application for clemency "very seriously" but defended his Government's tough stand on drug trafficking.

After a bilateral meeting with John Howard at Singapore's Istana - the official residence of President SRNathan, Mr Lee said the two leaders had discussed the plight of Van Tuong Nguyen, who lost his appeal against his death sentence last year.

"When we receive the petitions and consider them in cabinet, we will take into account all the points that are raised and consider them very seriously," he said.

But asked what his personal feelings were towards the plight of the 24-year-old, who was born in a Thai refugee camp after his mother fled the effects of the Vietnam war, Mr Lee offered little encouragement.

"This is a very serious offence and, you know, in Singapore we treat drug offences very, very seriously.

"Unless we do that, the number of lives which will be affected and destroyed by people who are hooked on drugs will be out of proportion to the benefit of whatever the drug dealer or the drug trafficker gets," he said.

"And so we have always taken a very firm line. It is the only way we can maintain Singapore as a drug-free and clean society."

Mr Nguyen was convicted of trafficking almost 400grams of heroin following his arrest at Singapore's Changi airport in December 2002, after transiting from Phnom Penh to Melbourne.

He later told authorities he had agreed to collect the drugs for a Sydney man to pay off his twin brother's debts.

Mr Nguyen's lawyers will file his clemency application next month. It could take a further three months before the cabinet and President Natham decide whether to cancel his date with Singapore's hangman.

However, the city-state has granted clemency in only half a dozen cases in the 30 years since the death sentence became mandatory for drug trafficking.

Possible tensions over the hanging of the Melbourne man could become the toughest obstacle to bilateral relations between the two countries for years.

But Mr Lee said yesterday that "on bilateral matters there are really not many problems to discuss".

"Overall our relationship is in good shape," he said.

Mr Howard used his first official visit to Singapore since Mr Lee, the son of founding father Lee Kwan Yew, became Prime Minister last August to bestow an honorary Companion of the Order of Australia on former leader Goh Chok Tong.