WASHINGTON (Reuters) - U.S. President Donald Trump on Thursday said he is exploring a delay in the 2020 census for an unspecified amount of time after the Supreme Court blocked, for now, his push to add a citizenship question to the decennial headcount.

“I have asked the lawyers if they can delay the Census, no matter how long, until the United States Supreme Court is given additional information from which it can make a final and decisive decision on this very critical matter,” Trump tweeted.

The national census is required every 10 years under the U.S. Constitution, which specifically mandates it. No citizenship question has been a part of the census since 1950.

The Trump administration had said it wants to add the question to better enforce a law protecting the voting rights of racial minorities.

Critics have called the question a Republican ploy to scare immigrants away from taking part and engineer an undercount in Democratic-leaning areas with large immigrant and Latino populations.

The nation’s top court, in a decision handed down on Thursday, said the federal government’s rationale for the question “seems to have been contrived” and stated the government had not given a reasoned explanation for its actions.

The Supreme Court sent the issue back to the Commerce Department, which is in charge of the census, to decide whether to provide a different rationale for the question.

The administration has said census forms need to be printed in the coming days. A federal agency normally takes weeks or months to issue a determination.