TOKYO, Sept 6 (Reuters) - Japan's Nikkei share average tumbled to a four-month low in early trade on Wednesday as risk appetite was sapped by a stronger yen on concerns about tensions between the United States and North Korea.

The Nikkei fell 0.7 percent to 19,254.67, the lowest level since May 1.

The broader Topix dropped 0.6 percent to 1,581.96.

A top North Korean diplomat warned that his country was ready to send "more gift packages" to the U.S. as world powers struggled for a response to Pyongyang's latest nuclear weapons test. (Reporting by Ayai Tomisawa; Editing by Chris Gallagher)