US border tsar Tom Homan said the immigration enforcement surge in Minnesota will end, telling reporters that President Donald Trump has approved his request to conclude the operation.

"I will also remain in Minnesota a little longer to oversee the drawdown, to ensure its success," Homan said during the news conference on Thursday morning.

Homan said Minnesota has become "less of a sanctuary state" since local officials have cooperated more with federal immigration officers.

The recent surge of more than 2,000 immigration officers to the state inspired nationwide protests after two US citizens were killed by federal agents last month.

Officials in Minnesota have been able to "greatly reduce the number of targets" for immigration enforcement, Homan said, adding that Operation Metro Surge was a "great success".

He mentioned the arrest of a number of undocumented immigrants, whom he referred to as "illegal aliens", including men he said were convicted of rape and other sexual misconduct. 

Homan said that Immigration and Customs Enforcement (ICE) has always had a presence in Minnesota and will continue to have one. 

"A small footprint of personnel will remain for a period of time to close out and transition full command and control back to the field office," he said.