HNR Acquisition (HNRA) said Tuesday it has regained compliance with the New York Stock Exchange's requirement for timely filing of financial reports, after submitting its annual report to the US Securities and Exchange Commission.

The upstream energy company also said it received from its independent public auditing firm an audit opinion with "going concern" qualification for its audited consolidated financial statements for the year ended Dec. 31, which were included in the filing.

HNR said the auditing firm raised concern about its "significant" working capital deficiency that requires it to raise additional funds to meet its obligations and sustain its operations. According to the firm, "these conditions raise a substantial doubt about the company's ability to continue as a going concern," HNR said.

To remove such doubt, the company said it plans to improve profitability through streamlining costs and "maintaining active hedge positions for its proven reserve production," and issue additional shares under a common stock purchase agreement with White Lion Capital.

Shares of the company slumped nearly 5.7% in recent trading.