“We're the two superpowers,” Trump told reporters as he departed the White House on Tuesday for the long flight to Beijing.

Taiwan, tariffs and the strait of Hormuz are on the meeting’s agenda for Beijing – but will the US president be forced to ask for help in ending his war with Iran?

The summit between US President Donald Trump and his Chinese counterpart Xi Jinping that begins on Wednesday in Beijing will unfold around an agenda concentrated on five main…