Television actress Lucy Lawless climbed aboard an oil-drilling ship Friday in New Zealand, joining six Greenpeace activists to try to stop the vessel from setting off for the Arctic.

Speaking from atop a 53-metre drilling tower aboard the Noble Discoverer in Port Taranaki, Lawless told The Associated Press on Friday that wind gusts were making it difficult to stay put but that she and the other protesters planned to stay there for "as long as we possibly can." She said she had a "little bit" of food and some provisions with her.

The protesters hung banners from the drilling derrick reading "Stop Shell" and “(hashtag)SaveTheArctic."

The ship is chartered by oil company Shell. Shona Geary, the company's New Zealand spokeswoman, said the ship was due to leave over the weekend for a drilling program in the Arctic but that all operations aboard had come to a stop.

"We are taking a very calm and measured approach to this," she said.

Police spokesman Grant Ogilvie said early Friday afternoon that five police officers boarded the ship. They had made contact with the protesters and were trying to determine their intentions. The port remained open but access was restricted, Ogilvie said.

"The protesters are clearly breaking the law by trespassing on the ship," said Police Inspector Blair Telford in a statement.

Lawless, 43, a New Zealander, is best known for her title role in "Xena: Warrior Princess." More recently she has starred in "Spartacus: Blood and Sand."

Lawless said she was taking direct protest action for the first time in her life to protest oil drilling and to draw attention to climate change.

"I've got three kids. My sole biological reason for being on this planet is to ensure that they can flourish, and they can't do that in a filthy, degraded environment," she said. "We need to stand up while we still can."

Greenpeace spokesman Nathan Argent said the ship was due to drill five exploratory wells during the Arctic summer. He said Greenpeace is concerned about the rush of companies trying to drill in the Arctic and the potential for catastrophic spills in the ecologically sensitive region.

"The oil companies are pushing the frontiers in the Arctic," he said. "There's a relentless push to get the last drops of oil."

In a statement, Shell said the actions of Greenpeace were jeopardizing everybody's safety.

"Shell has taken unprecedented steps to pursue safe, environmentally responsible exploration in shallow water off the coast of Alaska," the company said.