Australia must continue to rigorously enforce sanctions on North Korea ahead of what could be a historic summit with the US, the prime minister, Malcolm Turnbull, says.

Turnbull says there have been “many false dawns before” when it comes to the rogue nation so it is critical to maintain economic pressure.

“I emphasise those sanctions must remain in full force, rigorously enforced, until such time as the regime does start to denuclearise,” he said in McLaren Vale, South Australia on Saturday.

“It has got to make a commitment and demonstrate its commitment by actions to remove its illegal, dangerous and reckless nuclear capability and threat.”

Turnbull said the sanctions, along with a strong stand by the US president Donald Trump, had bought the North Korean leader, Kim Jong-un, to the table.

Labor’s defence spokesman, Richard Marles, agreed that existing sanctions had bitten North Korea.

“To that end, it’s really critical the campaign of maximum pressure through sanctions is maintained and there’s no letting up on that,” he said.

“If anything is going to change North Korean behaviour, it is that.”

South Korea’s National Security Office head, Chung Eui-yong, had told reporters at the White House on Thursday that Kim had committed to denuclearisation and to suspending nuclear or missile tests.

The White House spokeswoman Sarah Sanders said Trump “will accept the invitation to meet with Kim Jong-un at a place and time to be determined”.

But the US also says the meeting won’t take place unless there is concrete action to match North Korea’s words and rhetoric.

It’s expected the summit could take place in Panmunjom, the truce village in the demilitarised zone between North and South Korea.

Switzerland has also offered to host, and the former Australian prime minister Kevin Rudd has suggested Beijing as a possible host.

Rudd has a degree of scepticism about the meeting, but says it offers the opportunity to rewrite history.

He told the ABC on Saturday the meeting needed the right preparation, including around definitions of denuclearisation and what it would mean for future missile and nuclear testing programs.

He said the suggestions were that Trump was not approaching the idea of a summit with the caution and preparation needed, but he acknowledged the US president had his own way of doing things.

“He runs his own remarkable diplomatic style and, if you like, he’s meeting another leader in North Korea who has his own remarkable style as well,” he told the ABC.

“This could end spectacularly well, or it could end spectacularly badly.”

During his visit to the McLaren Vale wine region on Saturday, Turnbull also threw his support behind the South Australian opposition leader, Steven Marshall, ahead of next week’s state election.

He called for an end to the “failed leadership” of the Labor government

“How can you be in a position where you have the most expensive and the least reliable energy in Australia?” he asked reporters.

“The long and sorry era of Labor government in this state has let South Australians down.”

Turnbull said Marshall was an “absolute vital necessity” to the state, but would not comment on the future leadership of the party if Labor were to win a fifth consecutive term at the March 17 poll.