The international community has called for a de-escalation of tensions in Ukraine and a peaceful political resolution to its crisis after Crimea's Supreme Council decided on Thursday to hold a referendum on whether to join Russia.

U.N. special envoy to Ukraine Robert Serry "is continuing his consultations with Ukrainian and diplomatic interlocutors in Kiev," U.N. spokesman Martin Nesirky said Friday, adding that he will leave the Ukrainian capital on Saturday.

It is not yet known when Serry would return to Ukraine, but he will continue to promote the urgently needed de-escalation and a peaceful political resolution of the Ukraine crisis, Nesirky added.

Serry was dispatched last week by U.N. Secretary-General Ban Ki-moon to Ukraine and went to the crisis-gripped Crimea to take stock of and evaluate the situation in the heavily ethnic Russian region of southern Ukraine.

The spokesman described the announcement of a referendum on Crimea's future status as a worrying and serious development. "In this regard, the secretary-general urges the authorities in Ukraine, including in Crimea, to treat this matter with calm," he said.

On Thursday, Crimea's Supreme Council decided to hold a referendum on March 16, instead of March 30 decided previously, on whether to join Russia or remain part of Ukraine as an autonomous republic.

Grigory Ioffe, deputy parliament speaker of the crisis-hit autonomous republic of Crimea, said Friday that the region would not suffer economic woes if the southern Ukrainian republic chooses to join Russia at the March 16 referendum.

Ioffe said the referendum would be carried out in accordance with the current Ukrainian constitution, which stipulates that the Crimean people have the right to decide whether the republic will remain part of Ukraine or join the Russian Federation.

According to statistics of 2013, ethnic Russians or Russian-speaking citizens account for nearly 60 percent of the 2-million Crimean population. Ukrainians make up about 25 percent and Crimean Tatars account for 12 percent.

Crimea, host to Russia's Black Sea Fleet, has been at the epicenter of the ongoing crisis in Ukraine since Ukrainian President Viktor Yanukovych was ousted by parliament on Feb. 22.

Commenting on the simmering tensions in Crimea, Russia said Friday that they did not expect a new cold war and the West and Moscow could seek some common ground to solve the Ukraine crisis through dialogue.

Referring to the scheduled referendum on March 16, Russia said it reflected the common will of the Crimea people.

Russian Foreign Minister Sergei Lavrov on Friday warned the United States not to impose any sanctions on Moscow, as Washington would inevitably be hit in return.

Stressing Washington's commitment to supporting the Ukrainian people, U.S. Defense Secretary Chuck Hagel praised the performance and the restraint of the Ukrainian armed forces, saying that they did not allow the situation to escalate.

Hagel also pledged that he was committed to keeping a dialogue with his Ukrainian counterpart Ihor Tenyuh through these difficult times.

Tenyuh asked Hagel to consider providing some advice and counsel to the Ukrainian troops with respect to humanitarian assistance and disaster relief efforts.

Also on Friday, French President Francois Hollande discussed with Canadian Prime Minister Stephen Harper the situation in Ukraine, reiterating their support to the new Ukrainian authorities.

They stressed the full support of France and Canada "to the new authorities in Ukraine, as well as to the process of political transition, especially to the preparation under international control of the presidential election scheduled for May 25."

French Foreign Minister Laurent Fabius said on Friday that the planned referendum on the future of Crimea was contrary to Ukrainian Constitution and international law, adding what they expected was a de-escalation of tensions and dialogue between relevant parties. Endi