European High Representative for Foreign Affairs and Security Policy Federica Mogherini and NATO Secretary General Jens Stoltenberg | John Thys/AFP via Getty Images EU backs greater military cooperation Foreign policy chief wants to establish Europe as a ‘superpower that believes in multilateralism and cooperation.’

As U.S. President-elect Donald Trump began choosing his senior White House staff on Monday, EU officials agreed to push ahead with greater military cooperation outside the existing NATO alliance.

The plan for greater military cooperation, pushed by Germany, France, Italy and Spain, took on new urgency after Trump's victory last week. It could result in coordinated purchases of military equipment and the activation of an existing — but so far unused — jointly-operated rapid deployment force that presently consists of 1,500 troops.

Federica Mogherini, the EU foreign policy chief, on Monday said the plan would have gone forward regardless of the American election result. Mogherini has previously said the goal isn't to create a so-called EU army, but rather to establish Europe as a "superpower that believes in multilateralism and cooperation."

Mogherini and EU diplomats said they believed that greater military cooperation in Europe would be a welcome development in Washington, even for Trump, who has said he wants America's NATO allies to carry more of the alliance's financial cost.

Even London, after years of opposing any plan to strengthen EU defense for fear of weakening NATO, said it did not oppose the plan.

Monday's decision, at a meeting of EU defense ministers and foreign ministers in Brussels, authorizes officials to proceed with a plan known as "permanent structured cooperation," or Pesco. The decision allows European nations willing to engage in greater military cooperation to go ahead without waiting for the consensus of the others — a concept known as a "two-speed" approach.

Even late last week it was unclear if a deal would be possible, one EU diplomat said, highlighting the controversial nature of the discussion.

The Italian defense minister, Roberta Pinotti, said a two-speed approach was not necessarily the preferred option. “If Europe manages to go all together at the same speed, that's great," Pinotti said. "But if there are some reluctant members, as others are ready to take steps forward, I don't think there's anything to worry about."

A first outline of the plan for greater cooperation was presented in a Global Strategy document that Mogherini presented to EU leaders in June. On Monday, she presented ministers with a follow-up document that sets out a series of proposals for defense and security cooperation, including Pesco.

Ministers also tasked Mogherini with presenting additional proposals by mid-2017 “to strengthen the relevance, usability and deployability" of the EU’s so-called "Rapid Response" toolbox, including existing EU Battlegroups — the rapid response force that has not been deployed so far, mainly for financial reasons.

Even London, after years of opposing any plan to strengthen EU defense for fear of weakening NATO, said it did not oppose the plan.

NATO Secretary General Jens Stoltenberg has supported the European plan, saying that EU countries are partners, not rivals, in defense.

“Rather than planning an expensive new headquarters or dreaming of a European army, the best approach to the Trump presidency is for European countries to step up their own defense spending," the British defense secretary Michael Fallon told reporters. He noted that the U.K. spends 2 percent of its annual GDP on defense and, he said, "we need other countries to step up."

Concerns about an overlap with NATO have been expressed by the Baltic states and others. But NATO Secretary General Jens Stoltenberg has supported the European plan, saying that EU countries are partners, not rivals, in defense.

And the push to spend more on Europe's militaries is already in the cards.

In a piece for the Guardian on Sunday, Stoltenberg stressed how “this year, 22 NATO allies will increase defense spending, leading to a total of 3 percent increase in real terms. And I expect that next year we will see the third consecutive year of increased defense spending in Europe.”

One of the proposals is a new EU military headquarters that is still opposed by London. But even on that point, the U.K. expressed flexibility, provided it is used only for civilian missions, or so-called non-executive missions, Fallon said. And also on Pesco, the British were supportive.“Pesco is already a voluntary arrangement,” he said.

For the French, who have been pushing for greater defense integration, some diplomats have argued that it is also a way to offset Germany's economic dominance. For them, Monday's decision was a victory. “It's an important leap forward,” a French diplomat said. The French defense minister, Jean-Yves Le Drian, said: “I have always been in favor of an operative EU defense rather than a declarative defense.”

Diplomats, however, said it was unclear how long it would take between Monday's decision to explore Pesco and the actual implementation. Some also warned that a two-speed approach could have unpredictable consequences if divisions grow among European nations over the best approaches to military cooperation.