The latest World Congress Against the Death Penalty has stepped up pressure on world leaders, as the number of countries imposing the penalty falls but the overall number of people executed rises.

Key points: Pressure applied to Belarus, only country on European continent still using capital punishment

Pressure applied to Belarus, only country on European continent still using capital punishment Most executions are carried out in five nations, including China, US, Saudi Arabia

Most executions are carried out in five nations, including China, US, Saudi Arabia Number of countries imposing death penalty drops, overall number of people executed rises

Philip Ruddock, the Special Envoy for Human Rights, led Australia's delegation to the sixth world congress, in Norway.

He said there was strong interest in Australia's views, and there had been some progress in reducing the number of countries using the death penalty.

"There are smaller countries that … read the research that demonstrates that if you want to deter people, it's apprehension for an offence that is far more likely to influence behaviour, rather than the difference between a capital punishment or life in prison," he said.

"So these arguments, for which there is an enormous amount of research, are compelling in relation to countries that are at the cusp."

Most executions carried out in five nations

The congress applied more pressure for a global end to executions, including on Belarus, which is the only country on the European continent to still use capital punishment.

"Something like two thirds of the world's nations have abandoned capital punishment," Mr Ruddock said.

"A number of countries including the United States maintain it — there are only about five countries that execute most of the people that are executed worldwide."

Mr Ruddock said he expected there would be change.

"I genuinely believe that as China develops economically, as it has to accommodate very much the rule of law in its economic advances, it will also look at whether it can continue to be so isolated, executing something in the order of 2,000 people a year — more than the rest of the world put together," he said.

"When you look at the United States, it has been the subject of abolition in states, and there are further states that are considering it.

"I think many Americans are embarrassed that they continue to have some states that maintain capital punishment."

Mr Ruddock said if the United States abolished the death penalty, that would have "a very significant impact upon developments in the few countries that do execute considerable numbers".

"There's Saudi Arabia, Iran, Pakistan, Iraq, and China of course," he said.

"We've got a way to go but I think when it is unwound, it will come together very quickly."

Ruddock urges US and China as 'a friend'

Mr Ruddock said Australia had tried to use its influence over both China and the US to encourage them to stop executing people.

"I said to the United States, we're a friend, and we want you to know how your friends see your retention of this policy," he said.

"The ambassador says, 'Well, I've got to represent my nation, but at least we no longer execute minors.' I say, 'Well, that's a good thing.'

"I then went and saw a magnificent former Chinese ambassador to Australia … and I said, 'Madame Fu Ying, as a friend of China, I've just been talking to the United States as a friend, and I want you both to know we are critical of these policies and we hope you can change'.

"I believe when your friends suggest that maybe there's time for a change, you do start to think a bit more seriously about it.

Philippine president-elect continues pro-execution stance

In the Philippines, local and foreign human rights groups have expressed deep concern about incoming president Rodrigo Duterte's plans to reintroduce capital punishment, fearing an explosion of extrajudicial killings similar to those seen in the president-elect's hometown Davao.

United Nations' human rights chief Zeid Ra'ad Al Hussein this month urged Mr Duterte not to reintroduce the death penalty.

Mr Duterte won the country's presidential elections last month in a landslide, with the reintroduction of capital punishment touted as a key tool in his campaign to end rampant crime.

On Monday, Mr Duterte gave a lengthy speech in Davao hitting out at "stupid" human rights campaigners for criticising his plans to impose curfews on children being on the streets at night and to reintroduce the death penalty.

"These human rights [groups], congressmen, how stupid you are," he said.

"I believe in retribution. Why? You should pay. When you kill someone, rape, you should die."

Mr Duterte said tens of thousands of people would die, with security forces being given shoot-to-kill orders.

Since winning he has promised to give bounties to police for killing drug dealers, and also encouraged ordinary citizens to kill or arrest suspects.

ABC/AFP