The Arctic region holds huge economic potential but Russia also wants to cooperate with others to preserve its fragile environment, President Vladimir Putin says.

Putin, speaking Wednesday at the Third International Arctic Forum in the sub-polar city of Salekhard, pledged to work with the other "Arctic Five" nations to keep the polar region clean, even as the event was overshadowed by the arrest of 30 Greenpeace demonstrators attempting to storm a Russian oil rig in the Arctic Ocean.

he Russian president referred to the 2008 Ilulissat Declaration signed in Greenland by Russia, the United States, Denmark, Canada and Norway, in which they pledged in part to protect the Arctic's marine environment should new shipping routes be opened due to global warming.

"Let me remind you that in 2008, the 'Arctic Five', including Russia, issued a declaration that sets out the international legal base for responsible governance in the northern sea areas," Putin said. "I want to reaffirm today Russia's commitment to this declaration's principles, and also to our desire to do everything possible to make the Arctic in practice a territory of partnership, cooperation and dialogue between countries and between the public at the broadest level."

Putin assured attendees Russia takes its Arctic environmental responsibilities seriously as it seeks to exploit the vast oil and gas potential of the region.

The country has significantly boosted hydrocarbon extraction there in the last decade, discovering more than 1,000 oil and gas fields, while also identifying deposits of diamonds and other rare metals, The Moscow Times reported.

The Russian energy companies Rosneft and Gazprom are active there, with Rosneft partnering with foreign major such as ExxonMobil and Statoil on oil exploration.

Part of Russia's Arctic Environmental Protection Strategy calls for allowing only energy companies with "the most advanced technology and the financial resources" to be granted access to the Arctic, Putin said.

Moscow has earmarked around $45 million for an "ambitious" clean-up project in the Arctic, including the removal of diesel fuel reserves left by the Soviet military in the 1960s, which have been frozen into the permafrost.

"I also note that we plan to extend considerably the network of nature conservation areas in the Arctic region," the Russian leader said. "These specially protected natural areas currently make up around 6 percent of the Russian Arctic, nearly (124,000 square miles). Our plan is to increase this area several-fold."

As the delegates gathered in Salekhard, 30 Greenpeace activists were placed in pretrial detention in Moscow after investigators opened a piracy case against them, which could result in 15-year sentences.

Putin told reporters he didn't think the protesters were guilty of piracy, but deserved to arrested.

"I do not know the details of the incident. They are obviously not pirates, but formally, they did attempt to board the platform," he said. "Our law enforcement officers and border guards did not know who was using Greenpeace's name to try to board the platform.

"This coincided with the events that were taking place in Kenya [where scores of people were killed in a terrorist attack at a Nairobi shopping mall], so anything was possible and we didn't know just who these people were out there," Putin said. "What is clear is that they violated international law and came dangerously close to the platform."