WASHINGTON (Reuters) - A federal appeals court on Friday rejected a U.S. Justice Department attempt to revive a lawsuit accusing casino mogul Steve Wynn of lobbying then-President Donald Trump on behalf of China.

Wynn, the former CEO of Wynn resorts and finance chair of the Republican National Committee, no longer had an obligation to register because his alleged lobbying campaign ended in 2017, a three-judge panel of the U.S. Court of Appeals for the District of Columbia Circuit found.

The ruling upheld a lower court decision to dismiss the lawsuit, which sought to compel Wynn to retroactively register his lobbying activities with the U.S. government. Neither ruling addressed whether Wynn lobbied on behalf of China.

Wynn pressed the Trump administration in 2017 to cancel the visa of a Chinese businessperson who had sought asylum in the United States, according to the Justice Department's lawsuit.

Wynn has denied serving as a foreign agent.

A Justice Department spokesperson and a lawyer for Wynn did not immediately respond to requests for comment.

Two other people accused of being involved in the effort, former RNC fundraiser Elliott Broidy and rapper Prakazrel "Pras" Michel faced criminal charges for unregistered foreign lobbying. Broidy was later pardoned by Trump.

The Justice Department has sought to ramp up its efforts to curb foreign influence in the U.S. amid increasing tensions with Russia and China. The lawsuit against Wynn was the first affirmative civil lawsuit brought under the U.S. foreign agent law in more than three decades.

(Reporting by Andrew Goudsward; Editing by Alistair Bell)

By Andrew Goudsward