Former Binance chief Changpeng Zhao cannot leave the US for the time being, a federal judge said Monday, after the founder of the world’s largest cryptocurrency exchange pleaded guilty to violating US anti-money laundering laws.

Zhao will be required to stay in the US until the Seattle court considers whether he should remain through his sentencing hearing in February, or if he should be allowed to return to United Arab Emirates, where he is a citizen.

Zhao, who is also a citizen of Canada, stepped down as CEO of Binance last week after pleading guilty to willfully causing the exchange to fail to maintain an effective anti-money laundering program.

US District Judge Richard Jones in Seattle said he would review whether Zhao should have to stay in the US after the government appealed a decision by another judge to allow Zhao to return to the UAE before his Feb. 23 sentencing hearing. Zhao agreed to a $175 million bond as part of the bail agreement.

Binance Holdings agreed to pay over $4.3 billion and pleaded guilty to breaking US anti-money laundering and sanctions laws.

Binance said last week it had worked hard to make the company “safer and even more secure.” Lawyers for Zhao did not immediately respond to a request for comment on Monday.

Last week, Zhao conceded: “I made mistakes, and I must take responsibility.”

Zhao faces a maximum prison sentence of 18 months under federal guidelines and has agreed not to appeal any sentence up to that length. Prosecutors will take a position on how much jail time to seek closer to Zhao’s sentencing, a Justice Department spokesperson said last week.

The government had said it may be unable to secure Zhao’s return to the US given it has no extradition treaty with the UAE.

But lawyers for Zhao disputed that he was a flight risk, noting that he paid a “substantial” bail package and voluntarily came to the US to accept responsibility for his actions.