Shoei Kisen, the Japanese owner of the container ship blocking the Suez Canal, said it aims to free the ship "tomorrow night Japan time", the Nikkei reported on Friday.
The 400 m (430-yard) Ever Given, leased by Taiwan's Evergreen Marine Corp, is blocking transit through one of the world's busiest shipping channels for oil and grain and other trade linking Asia and Europe.
A spokeswoman for the owner in Japan said that the refloating work was ongoing but that the company did not yet know when the effort would succeed.
"We don't have an estimate for when the work will succeed," she said.