Lord Cameron’s administration forged close economic ties with China and leader Xi Jinping supped a pint with the then prime minister at a pub near Chequers in a sign of how close they were.
But Mr Sunak told a summit of global investors that his Government had a more cautious approach to engagement with Beijing.
The Prime Minister told the summit in Hampton Court Palace: “If David was here what he would say is the China of today is not the China he dealt with over a decade ago.
“It has changed, it’s right that our strategy evolves to take account of that.
“Our strategy can be summarised in three approaches: it’s to protect, align and engage.
“We have got to protect the UK against the risks, where they manifest themselves.”
The new National Security and Investment Act allows the Government to block investment in sensitive sectors.
The UK will “align with our allies” such as the US, Australia and Japan, Mr Sunak said.
But the UK would still engage because “whether you like it or not, China is an indisputable fact of global economic life”.
“There’s no solution to the world’s biggest problems – whether that’s climate change, regulating AI appropriately and safely, tackling global public health, macroeconomic stability – without engaging with China.
“If you have taken the steps you need to protect yourself then you should be able to engage with confidence to the benefit of our country.”
He said Lord Cameron’s return to frontline politics was useful given the level of global uncertainty. The global picture has become much more uncertain, more challenging than at any time in recent history.
“It’s one of the reasons I was delighted that David Cameron was rejoining government as Foreign Secretary, to have those relationships and experience at such a tricky time is enormously valuable to the Government.”