The Election Day development was the latest dizzying twist in a legal battle over the controversial rule that the Trump administration argues helps ensure those who are self-sufficient come to the country.

On Monday, US District Judge Gary Feinerman in Chicago struck down the rule and US Citizenship and Immigration Services stopped applying it to pending applications. Government attorneys appealed, and the 7th US Circuit Court of Appeals put a hold on the ruling the next day, allowing the restrictions to take effect again.

USCIS spokesman Matthew Bourke said on Wednesday that the agency would immediately restart applying the rule to pending cases, but not "re-adjudicate any applications or petitions that were approved" in light of Monday's decision.

Under the Trump administration rule, officials can deny permanent residency to legal immigrants over their use of food stamps, Medicaid or other public benefits. Green card applicants must show they would not be burdens to the country or "public charges".

Immigrant rights advocates deemed it a "wealth test", while health experts warned of poorer health outcomes and rising costs as low-income migrants chose between necessary services and trying to stay in the country legally.

The Illinois Coalition for Immigrant and Refugee Rights and Cook County filed the lawsuit in Chicago and planned to submit arguments to the appeals court this month.

"It is no surprise that Trump's team is attempting to remove barriers that would not allow enforcement of his unlawful public charge definition, even after the courts clapped back at him earlier this week," Cook County State''s Attorney Kim Foxx, whose office argued the case, said in a statement on Wednesday. "I have confidence that the law will prevail here and immigrants across America will be treated fairly as human beings while this gets sorted in the appeal process."

Democrat Joe Biden has promised to end the policy if he is elected president. The rule has already been heavily litigated.

In January, the US Supreme Court reversed a hold on the policy after lawsuits. However, enforcement was halted by a federal judge in New York because of the coronavirus pandemic. By September, the 2nd US Circuit Court of Appeals had reversed that hold and the rule took effect nationwide.