A New York judge on Monday ordered Donald Trump to immediately pay $364 million in penalties stemming from the state’s civil fraud case against him, delivering one of the most consequential financial blows of his career and sharply limiting his remaining legal maneuvering room.

The order enforces the core judgment from the case brought by New York Attorney General Letitia James, who accused Mr. Trump and the Trump Organization of systematically inflating the value of assets to obtain favorable loan terms from banks. While an appellate court earlier reduced the total penalty from more than $500 million, it upheld the central finding that Mr. Trump had engaged in persistent fraud. The judge’s latest ruling makes clear that the reduced amount, including accrued interest, is now due in full and without delay.

According to people familiar with the proceedings, Mr. Trump’s legal team had entered the courtroom expecting discussions over a payment schedule or temporary relief while additional appeals were pursued. Instead, the judge rejected further delays and warned that attempts to evade payment, including hiding or transferring assets, could expose Mr. Trump to contempt proceedings and potential imprisonment.

The ruling immediately intensified pressure on Mr. Trump’s finances. While he has long portrayed himself as extraordinarily wealthy, the judgment requires hundreds of millions of dollars in liquid cash, a demand that could force the sale or seizure of major properties if payment is not made. State authorities have broad powers to enforce civil judgments, including placing liens on real estate and compelling asset liquidation.

The case centers on financial statements that prosecutors said overstated the value of properties such as Trump Tower, Mar-a-Lago, and various golf resorts. Those statements were used over several years to secure loans on more favorable terms than Mr. Trump would otherwise have qualified for. At trial, the judge concluded that the discrepancies were not clerical errors but part of a sustained pattern of deception.

In addition to the monetary penalty, the judgment imposed significant operational restrictions. Mr. Trump is barred for three years from serving as an officer or director of New York companies and from obtaining loans from New York state-chartered banks. Legal analysts say those provisions could have lasting consequences for a real estate developer whose business model has historically relied on leverage and institutional financing.

Mr. Trump has denounced the case as politically motivated and has repeatedly attacked the judge and the attorney general. In public statements, he has framed the enforcement order as an attempt to damage him politically, particularly as he remains active in national politics. His allies have echoed those claims, while Democrats have pointed to the judgment as validation of long-standing criticisms of his business practices.

The immediate enforcement of the penalty comes amid a broader series of legal setbacks for Mr. Trump, who faces multiple civil and criminal matters across several jurisdictions. Legal scholars note that while civil judgments are typically resolved through financial remedies, judges retain discretion to impose strict enforcement measures when defendants are seen as using delay tactics or acting in bad faith.

Interest on the fraud judgment continued to accrue throughout the appeals process, contributing significantly to the final amount now due. That accumulation underscores a central irony of the case: Mr. Trump’s strategy of contesting the ruling at every stage ultimately increased the financial cost.

Whether Mr. Trump can marshal the required funds remains an open question. Some analysts speculate that he may seek outside investors or sell assets under time pressure, potentially at reduced values. Others suggest that prolonged enforcement actions could further complicate his political and financial future.

For now, the ruling marks a decisive moment in a case that has unfolded over several years. A judge has affirmed that the fraud findings stand, the penalties are real, and the time for delay has ended. How Mr. Trump responds, and whether he can meet the court’s demands, will shape not only the fate of his business empire but also the next chapter of his legal battles.