Joe Biden has withdrawn Donald Trump's attempt to ban TikTok from the US, heralding a new phase of relations with Chinese tech companies.

The president cancelled three executive orders that had sought to ban TikTok from the US and block US businesses from dealing with it and WeChat, another popular Chinese app.

In their place, he ordered the US Commerce Department to investigate any transactions with companies tied to a "foreign entity" that might pose an "unacceptable risk" to national security.

The new order is likely to mean more systematic scrutiny for such deals, with Mr Biden's officials hoping to avoid the court defeats suffered by his predecessor's attempts.

Mr Trump's demand that TikTok be sold off to an American company remains in place, but it is now unclear whether that will ultimately happen.

The app is still under investigation by the Committee on Foreign Investments in the US, which can order the unravelling of such deals.

The order says: "The People’s Republic of China, among others, continues to threaten the national security, foreign policy, and economy of the United States.

"The federal government should evaluate these threats through rigorous, evidence-based analysis and should address any unacceptable or undue risks consistent with overall national security, foreign policy, and economic objectives, including the preservation and demonstration of America’s core values and fundamental freedoms."

Mr Biden's officials have insisted that they plan to be just as tough as Mr Trump was on Chinese tech investments, but replace his sometimes ad hoc broadsides with a more legalistic approach.

Allies say that Mr Biden plans to rally other countries against Chinese tech, which has quickly spread across the world and been incorporated into the infrastructure of many developing countries.