BERLIN - Germany should step up its leadership on the international stage and liberalize its arms exports policy, including to consider sending weapons to Ukraine, the future chief of the Munich Security Conference, Christoph Heusgen, said in an interview.

Germany has come under fire for refusing to send weapons to Ukraine, unlike other Western allies, amid fears of a fresh Russian invasion. Germany has a long-standing policy of not exporting weapons to war zones rooted partly in its bloody 20th-century history and resulting pacifism.

Heusgen said that Berlin was showing political leadership in the crisis - for example reviving the Normandy format of talks with representatives from Ukraine, Russia, France and Germany.

But Germany should consider exporting weapons so Ukraine could defend itself, too, said Heusgen, the former senior German diplomat who will take over the MSC at the end of this year's event on Feb. 18-20. Using history as an excuse was no longer appropriate or even logical, he said.

"We make it too easy on ourselves, to say we have always done it that way so we continue," he told Reuters. "We have to have a debate about a more active German role in foreign policy, and security policy and (arms exports policy) is part of it."

Heusgen said that Russian President Vladimir Putin appeared to be stoking a crisis with Ukraine to boost his popularity back home but did not yet appear decided to act.

"He is looking closely how we will react," Heusgen said.

Germany, the second largest donor to the United Nations, had already shown more foreign policy leadership under former Chancellor Angela Merkel, said Heusgen - for example, being more active in Africa.

Asked if Europe should keep troops stationed in Mali, he said the West needed to draw lessons from the Afghanistan debacle and focus on supporting governments that respected good governance and human rights.

Europe must set an ultimatum to Mali's government, he said: either it starts implementing a previous peace deal with northern tribes and organized democratic elections "or we go out."

(Reporting by Andreas Rinke and Sarah Marsh; Editing by Leslie Adler) ((sarah.marsh@thomsonreuters.com; +53 5217 0928; Reuters Messaging: sarah.marsh.thomsonreuters.com@reuters.net))