US President Barack Obama has urged his successor Donald Trump to stand up to Russia if it deviates from US “values and international norms”.
Speaking in Berlin, Mr Obama said he hoped the US president-elect “does not simply take a realpolitik approach” to dealing with Russia.
But he said he was encouraged by Mr Trump’s insistence he will remain fully committed to the Nato alliance.
Mr Obama was speaking after talks with the German Chancellor Angela Merkel.
The two allies stressed the need for continued close co-operation between their two countries, as well as between the US and the European Union.
They had earlier issued a joint statement strongly defending globalisation.
Mr Obama is expected to hold talks with UK Prime Minister Theresa May and the leaders of France, Italy and Spain on Friday, before flying to Peru.
Mr Obama and Mrs Merkel said they discussed the crises in Ukraine and Syria, the fight against so-called Islamic State and transatlantic trade, as well as the outcome of the US election.
The two leaders have forged a strong partnership over the years, even surviving the revelation that American spies had listened to her mobile phone calls.
He has called her “probably… my closest international partner”.