What will Trump, Xi and Putin discuss at their first-ever trilateral meeting?

US President Donald Trump is set to take part in the first-ever trilateral meeting with Chinese President Xi Jinping and Russian President Vladimir Putin on the sidelines of the Asia-Pacific Economic Cooperation (APEC) Summit in Shenzhen next week.

The unprecedented gathering of leaders from the world's three biggest nuclear powers comes at a complicated juncture in relations among the three countries. According to media reports, nuclear disarmament and Iran are expected to top the agenda.

White House spokesperson Olivia Wales confirmed the planned meeting, saying Trump intended to discuss reducing nuclear weapons globally and describing nuclear proliferation as a dangerous development.

"The President has made it clear that, among other topics, he will discuss the reduction of nuclear weapons in the world. This proliferation, President Trump believes, is very dangerous," Wales was quoted as saying by CNN.

The last nuclear arms pact between Russia and the United States expired in February, removing caps on the two largest atomic arsenals for the first time in more than a half-century. Trump had rejected a call by Russia to extend the two-country deal for another year and called for "a new, improved and modernised" deal that includes China.

Although a concrete agreement is unlikely to emerge from the meeting, the engagement is being viewed as an opportunity to initiate discussions at the highest level.

According to a senior Trump administration official, the US President is expected to raise the issue of Iran with Xi and Putin but does not intend to discuss Russia's ongoing war in Ukraine during the trilateral engagement.

Before the trilateral meeting, Trump is also likely to hold bilateral talks with Xi, although no meeting with Putin is currently on the schedule.

Tesla chief Elon Musk is also expected to accompany Trump during parts of his China visit, with US officials citing his business interests in the country. However, he is not expected to attend the trilateral meeting, ABC News reported.

By agreeing to host the meeting, Xi may be calculating that the occasion offers an opportunity to showcase China's growing influence and international standing, according to an Associated Press report. 

The report added that, for the Kremlin, the planned trilateral engagement represents a coveted opportunity to project Russia as a superpower on par with Washington and Beijing.