The US national emergency to respond to the COVID-19 pandemic has ended as President Joe Biden signed a bipartisan congressional resolution to bring it to a close after three years.

The national emergency allowed the government to take sweeping steps to respond to the virus and support the country's economic, health and welfare systems.

Some of the emergency measures have already been successfully wound-down, while others are still being phased out. The public health emergency - it underpins tough immigration restrictions at the US-Mexico border - is set to expire on May 11.

The White House issued a one-line statement on Monday saying Biden had signed the measure behind closed doors, after having publicly opposed the resolution though not to the point of issuing a veto.

More than 197 Democrats in the House voted against it when the GOP-controlled chamber passed it in February. Last month, as the measure passed the Senate by a 68-23 vote, Biden let lawmakers know he would sign it.

The administration said once it became clear that Congress was moving to speed up the end of the national emergency it worked to expedite agency preparations for a return to normal procedures.

More than 1.13 million people in the US died from COVID-19 over the past three years, according to the Centers for Disease Control and Prevention.