The US and Russia have insisted they will not accept North Korea as a “nuclear state”, amid a series of missile tests by the East Asian nation and increased rhetoric from both Kim Jong-un and Donald Trump.

US Secretary of State Rex Tillerson and Russian Foreign Minister Sergei Lavrov spoke by phone on a myriad of issues, but both agreed on their stance regarding Pyongyang’s continued development of nuclear weapons despite United Nations sanctions.

State Department Heather Nauert said in a statement that “both sides agreed that they will continue to work towards a diplomatic solution to achieve a denuclearised Korean peninsula”.

However, on the same call on Tuesday, Mr Lavrov criticised President Donald Trump’s “aggressive rhetoric” towards North Korea, as many world leaders and the UN have before. Mr Trump has said in the past that the US will rain down “fire and fury” on North Korea.

The phone call comes on the heels of Russia’s offer to be a mediator between Pyongyang and Washington, fostering dialogue rather than trading barbs as Mr Trump and Mr Kim have been doing for several months.

The President has repeatedly called Mr Kim “Rocket Man” as Mr Kim continues to test missiles dangerously close to US ally Japan.

UN security council unanimously agrees new sanctions for North Korea

Late last week, the UN Security Council also unanimously passed - including votes from Russia and China who have closer ties to Pyongyang - more sanctions on North Korea, further limiting its oil supplies and slave labour market.

Mr Tillerson had previously said during a November news conference that North Korea’s fuel supply “is already quite constrained” as shown by “anecdotal evidence” and US intelligence sources which show cars lined up at petrol stations or certain stations closing that would normally have fuel.

The issue is that the country only has one refinery that operates internally, so it is heavily reliant on finished fuel imports.

Reuters that according to Chinese customs data, China exported no oil products to North Korea in November - something that was above and beyond UN sanctions requirements. Beijing also imported no North Korean iron ore, coal or lead in last months, the second full month of those trade sanctions, the data showed.

North Korea announces intercontinental missile launch Show all 13 1 /13 North Korea announces intercontinental missile launch North Korea announces intercontinental missile launch Pyongyang residents react after the news of the successful launch of the new intercontinental ballistic missile AFP/Getty Images North Korea announces intercontinental missile launch North Korea's leader Kim Jong Un signing an order to test-fire the newly developed inter-continental ballistic missile KRT via AP Video North Korea announces intercontinental missile launch A news broadcast displays Kim Jong Un's signed document AP North Korea announces intercontinental missile launch People cheer as they watch the news broadcast announcing Kim Jong Un's order to test-fire the new inter-continental ballistic missile AFP/Getty Images North Korea announces intercontinental missile launch Residents react after the document signing AP North Korea announces intercontinental missile launch Pyongyang residents celebrate Kim Jong Un's announcement AFP/Getty North Korea announces intercontinental missile launch Cheering Pyongyang residents react AP North Korea announces intercontinental missile launch To counter North Korea's missile test, South Korea fired missiles into the East Sea The Defence Ministry/Yonhap via REUTERS North Korea announces intercontinental missile launch The Hyunmu-2 missiles firing during the drill South Korean Defense Ministry vi North Korea announces intercontinental missile launch The exercise was carried out in an attempt to counter Kim Jong Un's order South Korea Defense Ministry via AP North Korea announces intercontinental missile launch The South Korean army continue to carry out military exercises AP North Korea announces intercontinental missile launch Where K-9 self-propelled howitzers were taking part in a drill Rex Features North Korea announces intercontinental missile launch US soldiers are also present in the border city of Paju AFP/Getty Images

China has not disclosed its crude exports to North Korea for several years, but industry sources say it still supplies about 520,000 tonnes, or 3.8m barrels, a year to the country via an ageing pipeline.

A day after the UN sanctions, North Korea’s state media called the stricter controls “an act of war” by a “frenzied” Trump administration.

The US Treasury Department also released a statement regarding the US-specific sanctions on the country. Treasury Secretary Steve Mnuchin said the department’s finance-related sanctions will be “targeting leaders of North Korea’s ballistic missile programmes”.

Tensions have continued to rise between North Korea and the US, as Pyongyang tested an intercontinental ballistic missile on 29 November that US intelligence officials said would put all of the US mainland within striking range.