Israel vows to 'act accordingly' as Thunberg sails toward Gaza on Palestinian-flagged vessel

Thunberg, 22, a Swedish eco-warrior, set sail this week aboard the Madleen hoisting a Palestinian flag with 11 other activists. It will try to reach the shores of the Gaza Strip to bring in some aid and raise awareness over the humanitarian crisis there. 

"We are doing this because, no matter what odds we are against, we have to keep trying," Thunberg said.

Defrin did not disclose any details of how Israel would respond to Thunberg's arrival. 

Among those joining the crew of the Madleen are "Game of Thrones" actor Liam Cunningham and Rima Hassan, a French member of the European Parliament who is of Palestinian descent. She has been barred from entering Israel due to her active opposition to the Israeli assault on Gaza.

During her voyage, which began in the Sicilian port of Catania in southern Italy, Thunberg has been filming content for social media, including swimming in the sea.

"Because the moment we stop trying is when we lose our humanity. And no matter how dangerous this mission is, it's not even near as dangerous as the silence of the entire world in the face of the livestreamed genocide," she said before setting sail. 

The Associated Press contributed to this report.