Russian President Dmitry Medvedev has joined American and other European leaders in calling for Moammar Gadhafi to step down from power, CNN reported.

The move appears to indicate a closing diplomatic window for the longtime Libyan strongman.

Moscow has been a strong critic of the NATO-led mission in Libya, arguing that the scope of the organization's air campaign against Gaddafi's forces far exceeds the civilian protection mandate approved by the UN Security Council.

Medvedev's call for Gaddafi to step aside came at the end of the Group of Eight summit in Deauville, France, on Friday. The G8 includes the United States, the United Kingdom, France, Canada, Japan, Germany, Italy and Russia.

The G8 leaders also issued a written statement Friday expressing support for the democratic uprisings in the Middle East and North Africa.

His statement came on the heels of a request from the other G8 leaders to have the Russian leader mediate a settlement.

Earlier, Gaddafi's government also called for a Russian mediation, a sign that the Libyan leader may be searching for a way to bring about an end to the months-long war.

Libyan Prime Minister Al-Baghdadi Ali al-Mahmudi asked for help in achieving a cease-fire and starting talks without preconditions, according to a statement posted late Thursday by the Russian Foreign Ministry.

During that conversation, Foreign Minister Sergei Lavrov said Libya would have to comply with the Security Council mandate and stop any action that would cause harm to civilians, the statement said.

Libya is widely believed to have sought Russia's assistance because Moscow has consistently been a staunch critic of the NATO-led bombing campaign since that effort began in March.

On Wednesday, the Russian Foreign Ministry called NATO's recent bombing of certain Tripoli targets a "flagrant deviation" from U.N. Security Council resolution 1973.

That resolution authorizes all means necessary, short of occupying forces, to enforce a no-fly zone and protect Libyan civilians from attacks by forces loyal to Gadhafi.

Russia, a permanent member of the Security Council, abstained from the vote on the resolution.

US President Barack Obama, who had an extended private meeting with Medvedev while in France, insisted Friday that "the U.N. mandate of civilian protection cannot be accomplished when Gadhafi remains in Libya directing his forces in acts of aggression against the Libyan people."

"We are joined in resolve to finish the job," he declared.

A spokesman for Libya's transitional government said Gaddafi must leave before the opposition could consider negotiations or a cease-fire.

"There is no more room for him in or near Libya," said Jalal el-Gallal, a spokesman for the National Transitional Council.