Speaking at a news conference, Tsunakawa sidestepped questions over whether a Chapter 11 filing for Westinghouse was a possibility, saying there were "various options" for the unit.

Toshiba said earlier it would speed up looking at whether to sell a majority of Westinghouse, which has become the epicenter of Toshiba's latest crisis and an expected $6.3 billion writedown.

(Reporting by Makiko Yamazaki and Taiga Uranaka)