Guess who's coming to dinner? What Scott Morrison will say to Donald Trump

Prime Minister Scott Morrison will lobby Donald Trump to join a global campaign to slap sweeping new restrictions on social media giants during a private meeting where he will also push the US President to end his escalating trade war with China.

Mr Morrison will dine with Australia's key international ally on Thursday evening, as world leaders gather in Japan for one of the most important G20 summits in a decade.

US President Donald Trump and Prime Minister Scott Morrison. Credit: AAP

"Australia and the United States have different but complementary roles to play in the Indo-Pacific," Mr Morrison said before his flight to Osaka.

"From efforts to relieve the strains on our global trading system to greater digitalisation and the need for social media companies to step up to better protect our citizens, the US and Australia have significant roles to play."

The Prime Minister vowed to tackle violent extremism online after the deadly Christchurch terrorist attack, which Australian alleged gunman Brenton Tarrant live-streamed on Facebook, to the horror of national security officials.

While he does not expect to seal an immediate agreement to extend Australia's recent crackdown on social media groups and violent extremism to other countries, Mr Morrison will discuss the issue with Mr Trump hours after landing in Osaka and will also raise it during a broader session involving world leaders on Friday.

The dinner is also expected to be attended by a suite of major US players including Secretary of State Mike Pompeo, Treasury Secretary Steve Mnuchin, trade representative Robert Lighthizer, national security adviser John Bolton and Mr Trump's daughter and senior adviser Ivanka Trump.

The US and Australian leaders are also expected to discuss the worsening situation in Iran and Mr Trump's efforts to curb North Korea's nuclear ambitions.

Mr Morrison said the meeting "highlights the strength and candour of our relationship".

"Working together with [Japan's] Prime Minister [Shinzo] Abe as this year’s G20 host, the President and I will be working to make progress on the key issues facing the international community," Mr Morrison said. "It is in our interest to continue working together with other players to advance regional stability and prosperity."

Parliament passed tough new laws before the May election allowing social media executives to be jailed and their companies hit with billions of dollars in fines in the event of a repeat of the Christchurch incident.

The laws created a criminal offence for platforms that fail to rapidly remove "abhorrent violent material". Executives found personally liable could be jailed for three years, while companies could be fined up to 10 per cent of their annual global turnover.

The US, which is home to most of the world's biggest social media companies, has by far the most powerful hand in ensuring their regulation.

Mr Morrison wrote to Mr Abe in March flagging his intention to make his Australian social media crackdown an issue for world leaders.

"It is unacceptable to treat the internet as an ungoverned space," Mr Morrison wrote at the time.

"It is imperative that the global community works together to ensure that technology firms meet their moral obligation to protect the communities which they serve and from which they profit."

Mr Trump has also slated one-on-one events with Russian President Vladimir Putin, Saudi Crown Prince Mohammed bin Salman and Indian Prime Minister Narendra Modi.

His most anticipated meeting, though, will be with Chinese President Xi Jinping, who is locked in a high-stakes battle with Mr Trump over trade that threatens to dent global economic growth.

China's ambassador to Australia on Wednesday vowed his country would "fight to the end" in its trade war with the US, adopting a defiant stance even as Mr Morrison urged the superpowers to calm tensions.

In a speech in Canberra, Cheng Jingye squarely blamed Washington for the rising temperature, despite China's own widely criticised trade practices such as intellectual property theft, domestic subsidies and the forcing of foreign investors to hand over their technology know-how.

"China is willing to work together with the US to reach a win-win solution on the basis of equality and mutual respect," Mr Cheng told the Australia China Business Council.

"As we have made it clear, China's open to negotiations, but we will also fight to the end if needed."

Mr Morrison will be supported in Japan by Trade Minister Simon Birmingham, Finance Minister Mathias Cormann and Australia's outgoing ambassador to the US, Joe Hockey.