Sunday night, under pressure from both parties, outgoing US President Donald Trump signed a COVID-19 relief package worth $900 billion.

Trump also signed the Federal Agency Funding Act, which will prevent a government shutdown, according to a White House statement.

Millions of Americans affected by the COVID-19 pandemic were facing the risk of losing unemployment benefits Sunday, due to Trump's earlier refusal to sign the massive economic stimulus package approved by Congress.

The order also threatened a government shutdown by Tuesday because the relief package is part of a larger spending bill, although MPs could have agreed to another temporary extension to keep the government running.

Two federal unemployment benefits programs approved in March as part of an initial relief plan to tackle the Coronavirus expired at midnight Saturday, cutting aid to nearly 12 million Americans, according to the Century Foundation Research Center.

The $ 900 billion relief package approved by Congress overwhelmingly Monday after months of negotiations will extend those benefits, as well as other benefits that are set to expire in the coming days.

But the day after the bill was approved, Trump had thwarted all hopes that resulted from the long-delayed efforts of lawmakers, describing the bill as a "disgrace" in a video posted on Twitter, and initially indicating that he would not sign it.

Trump called for checks issued to Americans to be worth $2000 instead of the bill's allotted $600, and indicated that the legislation includes a lot of extra spending on programs not related to the issue.

From the Maralago resort in Florida where he spent the Christmas holidays, Trump on Saturday repeated his concerns in a tweet.

Meanwhile, President-elect Joe Biden, who is due to be sworn in on January 20, warned of "serious consequences" on Saturday if Trump continued to refuse to sign.

- 'Anarchy and misery' -

Some Republicans urged Trump to change his mind, noting that the bill was the result of a grueling compromise.

Republican Senator Pat Tommy told Fox News Sunday, "I understand that he wants people to remember him by calling for big checks, but the risk is that he will remain in memory because of the chaos, misery and erratic behavior."

In theory, Congress could have overruled Trump's veto.

Democrats in Congress on Thursday sought to approve a measure to increase direct payments in line with what Trump wanted, but Republicans blocked its passage.

This was largely seen as a theatrical move intended to expose the rift between Republicans and the outgoing president with little hope of adopting the measure.

And Senator Bernie Sanders said earlier Sunday, before Trump's signing, that "what the president is doing now is incredibly cruel."

He told ABC that Trump's behavior "is losing millions of people with expanded unemployment benefits."