Secretary of State John F. Kerry, left, and Secretary of Defense Chuck Hagel speak before addressing the Munich Security Conference at the Bayerischer Hof Hotel. (Brendan Smialowski/AFP/Getty Images)

In an unusual joint appearance overseas, Secretary of State John F. Kerry and Defense Secretary Chuck Hagel told European allies Saturday that Washington would depend more heavily on them to tackle a litany of political and security crises, even as the two pushed back against concerns that the Obama administration was abdicating leadership on the same issues.

The two senior members of Obama’s Cabinet told a gathering of world leaders, business executives, journalists and others at the annual Munich Security Conference that a “transatlantic renaissance” was necessary to confront an array of challenges, from climate change to violent extremism in the Middle East and collapsing states in Africa.

In contrast with past lectures from U.S. officials, Kerry and Hagel did not hector European countries to simply boost military spending or send more troops to hot spots around the world. Instead, the U.S. leaders exhibited an uncommon measure of humility, gently urging rather than exhorting their European allies to work together to project their influence over Syria, Iran and Afghanistan.

“In order to meet today’s challenges both near and far, America needs a strong Europe, and Europe needs a committed and engaged America,” Kerry said. “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.”

The Americans encountered some concern, however, that the Obama administration was retreating from Washington’s traditional leadership role in security matters, citing its unwillingness to become directly involved in the civil war in Syria or the popular uprising in Ukraine.

Josef Joffe, a German columnist, questioned whether the Obama administration had begun a “cycle of withdrawal” from global affairs. And the host of the conference, Wolfgang Ischinger, a former German ambassador to Washington, slyly asked whether the administration had decided to stop pressing NATO allies so loudly to revive their flagging defense budgets.

In response, Kerry ticked off a long list of global and regional conflicts in which Washington was still playing a leading role.

“This narrative, which has frankly been pushed by some people who have an interest in saying the United States is on a different track, I will tell you it is flat wrong,” Kerry said. “You name the issue. I can’t think of a place in the world from where we’re retreating.”

In particular, Kerry offered an elaborate defense of his frequent visits to the Middle East to try to secure a long-elusive peace accord between Israel and the Palestinians. Asked whether he was optimistic that a peace deal was possible, Kerry demurred but said it was imperative to try.

“I will tell you I’m hopeful. I believe in the possibility. I don’t believe we’re being quixotic,” he said. “We’re working hard because the consequences of failure are unacceptable.”

The Obama administration so far has been less outspoken about the crisis in Ukraine than some of its European allies, but during their visits to Europe this week, both Kerry and Hagel raised the issue several times in meetings with European leaders. Later Saturday, Kerry met in Munich with opposition leaders involved in the massive street protests against the government of President Viktor Yanukovych and reiterated U.S. support for their efforts to defend democracy and choice for Ukrainians, a senior State Department official said.

The protests began after Yanukovych abruptly walked away from a proposed trade deal with the European Union in favor of closer ties with Moscow.

“Nowhere is the fight for a democratic, European future more important today than in Ukraine,” Kerry said before the meeting. “The vast majority of Ukrainians want to live freely in a safe and a prosperous country. They are fighting for the right to associate with partners who will help them realize their aspirations.”

The secretary also met separately with Ukraine’s foreign minister, Leonid Kozhara, and expressed to him his “grave concerns” about the human rights situation in the country, the State Department official said.

Although Kerry and Hagel shared the stage in Munich, Hagel acknowledged that he has taken a lower profile in the foreign policy arena than his predecessors. After 12 years of war in Iraq and Afghanistan in which the Pentagon took a primary role in foreign policy, he said the Obama administration had decided that it is time to place more emphasis on traditional diplomacy.

“Over the last year, John and I have both worked to restore balance to the relationship between American defense and diplomacy,” Hagel said as he sat next to Kerry. “The transatlantic partnership has been successful because of the judicious use of both diplomacy and defense.”

Anne Gearan in Washington contributed to this report.