TOKYO, Aug 18 (Reuters) - Japan's Nikkei stock index skidded to its lowest in three months in early trade on Friday, after a selloff on Wall Street.

The Nikkei was last down 1.2 percent, after falling to its lowest since May 18.

On Thursday, the S&P 500 logged its biggest daily percentage drop in three months as escalating worries about the Trump administration's ability to push through its economic agenda rattled investors. (Reporting by Tokyo markets team; Editing by Richard Pullin)