New Delhi, Aug. 1 -- US President Donald Trump has appealed a federal judge's ruling that questioned the legality of his $10 billion lawsuit against the Internal Revenue Service (IRS), according to court filings reported by NBC News.

The notice of appeal, filed on Friday in the US District Court in Miami, challenges a July 13 order by US District Judge Kathleen Williams, who said the lawsuit had been filed for an "improper purpose" and was aimed at providing judicial legitimacy to a settlement that lacked a legal basis.

The lawsuit, brought by Trump, his sons Donald Trump Jr and Eric Trump, the Trump Organization and their attorneys, stemmed from the leak of Trump's tax records by a former IRS contractor. The contractor pleaded guilty i...