Regulatory concerns surrounding Binance US have reportedly culminated in investors backing out of a $100-million funding round.

The failed funding round also prompted Binance US CEO Brian Brooks’ surprise decision to step down after serving as its executive for just three months. 

Brooks, the former Acting Comptroller of the Currency and former chief legal officer to rival exchange Coinbase, cited “strategic differences” after stepping down. The funding round had been intended as the first step in Binance US’ path toward an initial public offering (IPO).

According to The New York Times, Brooks had initially courted potential investors, including Ray Lane from venture capital firm GreatPoint, and an executive at Japanese holding company SoftBank, under assurances that Binance US would comply with all United States regulatory guidelines.

However, the investors reportedly backed out due to concerns surrounding Binance CEO Changpeng Zhao’s 90% ownership stake in Binance’s U.S.-based exchange, alongside anxieties regarding an ongoing investigation from U.S. authorities that is reportedly scrutinizing Binance over money laundering and tax issues.

The New York Times also reports that a lack of clear separation between the operation of Binance and Binance US sparked concern among the investors.

Brooks publicly announced his resignation via an Aug. 7 tweet. A spokesperson for Binance US stated that the company would continue to take steps toward its goal of completing an IPO in the United States.

An IPO from Binance US would put the exchange on better footing to compete with Coinbase, which completed its own IPO on April 14. Zhao hoped the investment round would allow Binance US to gain a better footing with U.S. regulators to enable the IPO to proceed.

Despite the recent troubles, Zhao still appears confident that Binance US will be able to attract the investments it needs and have an IPO. He told Bloomberg in an interview on Thursday that there is still interest from “top-level” investors, adding:

“Binance.US also aims to IPO in the not too distant future […] It’s just a matter of time.”

Binance has been under regulatory pressure in a range of jurisdictions in recent months. The Financial Conduct Authority (FCA) in the United Kingdom demanded Binance halt all regulated activities in the U.K. at the end of last June. As a result of the FCA’s demand, major banks, including HSBC UK, have cut credit purchases to Binance.

Related: Binance reportedly halts pounds sterling withdrawal for UK customers again

Binance halted operations in Ontario, Canada in June after the provincial government took a hard stance against cryptocurrency trading in general. Crypto exchanges Bybit and KuCoin have also come under heavy fire from legislators in the Canadian province.

Further, Binance elected to remove support for the Korean won and halt Korean language support services last week as South Korea prepares to tighten its crypto regulations.

On July 3, the Thailand Securities and Exchange Commission also issued a criminal complaint again Binance for illegally operating a digital asset business in the country. The Thailand SEC reportedly issued several warnings that were ignored by the exchange.