The "game changer" in the sanctions effort to force North Korea to the negotiating table and deter its nuclear ambitions is China reducing oil exports to the rogue regime, Australian Foreign Minister Julie Bishop says.
Ms Bishop, at an Asia Society event hosted by former political rival and prime minister Kevin Rudd in New York on Friday, said China, North Korea's most important trading partner, was "engaged in very serious dialogue" with the US on finding a solution to the crisis.
"I actually believe oil is the game changer in the sanctions regime," Ms Bishop said.
"China is clearly open to using its undoubted leverage - economic leverage.
"I'm not suggesting diplomatic, but economic leverage over North Korea and from my discussions with the US administration I'm confident the US and China are engaged in very serious dialogue about how they are going to bring North Korea to the negotiating table."
Ms Bishop has been in New York the past week representing Australia at the United Nations General Assembly.
She has had discussions with US President Donald Trump, US Secretary of State Rex Tillerson and US Ambassador to the UN Nikki Haley.
Ms Bishop praised Mr Trump for persuading China to become involved in the effort to force North Korean leader Kim Jong-un to end his nuclear and missile program.
"It's worth noting up until the Trump administration's inauguration China was of the view that this was not their problem," Ms Bishop said.
"This was an issue between Pyongyang and Washington.
"I think China has now become part of the group working on the solution."
On September 11 the UN Security Council, including permanent member China, approved stringent sanctions on North Korea including reducing about 30 per cent of oil provided to North Korea.
China is the main supplier of oil to North Korea.
"I think economic sanctions will get tougher," Ms Bishop said.
"The United States has announced they will do more.
"I believe China will do more and we need Russia to be inside the tent and Australia of course will play its part."
