US border authorities will have the right to deport migrants who have illegally entered the country without first reviewing their asylum applications in certain cases.
This is the main point of the new presidential decree signed by Joe Biden.
The new decree will take effect if more than 2,500 migrants per day enter the US. In practice, this means it will take effect immediately, as the daily numbers are currently higher than that.
The restrictions will remain in place until the numbers fall below 1,500 per day over a seven-day period. Migrants who are not deemed to be in danger of deportation can be removed from the US just an hour after crossing the border. They also risk being banned from returning for five years.
The decree had leaked to the media before the official announcement and Biden is described as one of the toughest Democratic presidents on the issue of migration.
The rule change comes at a time when all signs point to the presidential election in November being between Biden and Republican former President Donald Trump. Trump, who has a small lead in opinion polls, is known for his restrictive migration policy.
Biden accused Republicans of "extremely cynical and political" actions by not cooperating with the president and blocking billions of dollars to strengthen the border with Mexico – to strengthen Trump's chances in the fall election.