MUNICH (AFP) - United States Secretary of State John Kerry called for a "transatlantic renaissance" in which the United States and Europe jointly tackle shared threats, from wars and poverty to climate change.
"In order to meet today's challenges both near and far, America needs a strong Europe, and Europe needs a committed, engaged America," Mr Kerry told a security conference in Germany. "That means turning inward is not an option for any of us. When we lead together, others will join us. But when we don't, the simple fact is few are prepared or willing to step up."
Transatlantic ties have been seen to be cooling amid what analysts call Washington's strategic "pivot to Asia" and a shifting international power balance with the emergence of new global players such as China, Russia and Brazil.
Many European leaders have opposed Washington in recent years over the Iraq war, abuses in Guantanamo Bay and, more recently, the sweeping NSA surveillance scandal. The defence alliance Nato is seen as war-weary by many after 13 years in Afghanistan, where its major combat operations are set to end this year, while the US has increasingly relied on EU allies in Libya and other African missions.
Mr Kerry, in his speech, cited milestones such as the fall of the Berlin Wall 25 years ago, calling the transatlantic relationship "the most productive partnership in the history of international affairs".
"As a transatlantic community, we cannot retreat - and we must do more than just recover.
"What we need in 2014 is a transatlantic renaissance - a new burst of energy, commitment and investment in the three roots of our strength: our economic prosperity, our shared security, and the common values that sustain us."
Mr Kerry cited joint US-European efforts - on the war in Syria, the Middle East conflict, Iran's nuclear programme, political turmoil in Ukraine, and spoke of a joint responsibility to combat climate change.
He said a key project would be the Transatlantic Trade and Investment Partnership (T-TIP), a US-EU trade deal being negotiated that would be the world's biggest.
"If we are ambitious enough, T-TIP will do for our shared prosperity what NATO has done for our shared security, recognising that our security has always been built on a foundation of shared prosperity," he said.