US President Joe Biden has signed his $US1.9 trillion ($2.4 trillion) stimulus bill into law, commemorating the one-year anniversary of a US lockdown over the coronavirus pandemic with a measure designed to boost the economy.

The Democratic-led US House of Representatives gave final congressional approval to the measure on Wednesday, handing the Democratic president a major victory in the early months of his term.

“This historic legislation is about rebuilding the backbone of this country,” Mr Biden said before signing.

Mr Biden signed the measure before a prime-time speech he plans later on Thursday to herald the anniversary of the lockdown, urge vigilance as the pandemic rages and offer hope amid a growing number of vaccinated people across the country.

Tweet from @WhiteHouse

Mr Biden’s signing of the legislation, called the American Rescue Plan, had initially been scheduled for Friday but White House chief of staff Ron Klain said it was moved up after it arrived at the White House on Wednesday night.

“We want to move as fast as possible,” Klain posted on Twitter.

A celebration with congressional leaders would still take place on Friday, he said.

The package provides $US400 billion for $US1,400 direct payments to most individuals, $US350 billion in aid to state and local governments, an expansion of the child tax credit and increased funding for COVID-19 vaccine distribution.

About 530,000 people have died from COVID-19 in the United States and about 10 per cent of the population has been fully vaccinated.

Mr Biden said on Wednesday he would use his 8pm address to discuss “what we’ve been through as a nation this past year”.

“But more importantly, I’m going to talk about what comes next. I’m going to launch the next phase of the COVID response and explain what we will do as a government and what we will ask of the American people,” Mr Biden said.