The announcement comes two weeks after the US president unveiled a sweeping crackdown at the Mexican border, which effectively halted asylum claims for those arriving between officially designated ports of entry.
Mr Biden has described his border policies as the “toughest” ever. The government has been grappling with a record influx of illegal migrants into Texas, Arizona and California, many of whom travelled to South America to attempt the crossing.
The American asylum system is plagued by a backlog of more than two million cases. Some Republican governors of southern states have paid to transport migrants north to Democrat-controlled areas including New York, Chicago and Washington DC.
The southern border has become a major campaign issue for both Mr Biden and Trump, who has pledged to bring back plans for a border wall and deploy troops to deter those crossing into the US.
“Biden is preparing to give mass amnesty to hundreds of thousands of illegal aliens,” Trump said on his Truth Social platform on Monday after the plans were first reported.
Karoline Leavitt, the Trump campaign national press secretary, said on Tuesday that the plan would “undoubtedly lead to a greater surge in migrant crime, cost taxpayers millions of dollars they cannot afford, overwhelm public services, and steal Social Security and Medicare benefits from American seniors to fund benefits for illegals”.
“Biden doesn’t care about the American lives that will forever be destroyed by the illegal criminals he is importing,” she said.