Foreign Minister Murray McCully has added his voice to international calls for restraint and for the Security Council to take the lead to prevent any further escalation of tensions between Russia and Ukraine.

Mr McCully said developments in Ukraine over the weekend were "deeply worrying" after reports Russian military were mobilising in Crimea, which is part of Ukraine but where Russia has a naval base.

Russia's President Vladimir Putin has also secured Parliament's signoff to invade Ukraine, claiming it could be necessary to protect the interests of Russian citizens. That has prompted Ukraine to put its Armed Forces on high alert and increase security at military and nuclear bases.

President Barack Obama called on President Putin to withdraw its forces in a phone call.


Mr McCully said all parties involved should exercise restraint and refrain from any action that could escalate tensions.

"The sovereignty and territorial integroty of Ukraine must be respected and maintained. The UN Security Council is the appropriate body to take the lead and we expect the Council to live up to its responsibilities."

New Zealand is in the process of free trade talks with Russia and Labou leader David Cunliffe said it was possible that would be affected if the situation escalated. "If Russia were in a situation where it was taking significant aggressive acts, then that is a question that could potentially arise. It would be hard to carry out business as usual if there was a shooting war going on."

He said there was little New Zealand could do other than back the United Nations, but it should offer to support the UN's efforts practically in any way it could, because of its record in peacekeeping and diplomacy.

He said all parties should resolve the issues over Crimea through diplomatic rather than military means.

"We would ask the UN to lend its good offices to a peaceful resolution, asking Russia to respect the territorial integrity of Ukraine, and hoping this does not escalate into armed conflict."