BRUSSELS – Turmoil in Greece is forcing other eurozone countries to consider the prospect that it might soon leave the single-currency club.

Jean-Claude Juncker, president of the group of finance ministers for the 17 euro countries, told reporters early today at the end of a summit of European leaders here that the eurozone countries “have to consider all kinds of events.” But he insisted that “the working assumption” was that Greece would remain part of the euro.

The statement by Juncker, Luxembourg’s prime minister, was a frank admission that Greece could wind up abandoning the euro as its currency, a prospect that many analysts fear could cause investors to doubt the financial viability of other weak members of the eurozone.

However, Juncker said he had not asked the euro nations to prepare national contingency plans for a possible chaotic departure of Greece from the currency.

Belgian Finance Minister Steven Vanackere said that “to say that we do not prepare for eventualities would not be a responsible attitude. I believe many countries have contingency plans when it comes to things they want to avoid at all cost, like a terror attack. And to say that we have no contingency plans would be irresponsible.”

At the end of a summit dinner of the 27 European Union nations, EU President Herman Van Rompuy said that all EU leaders want Greece to remain in the eurozone, while respecting its commitments to pay back its debt. Van Rompuy said the EU needed to concentrate more on coordinating its policies to promote economic growth, to step up investments and credit to small and medium-sized businesses, and to focus on job creation.

French President Francois Hollande said EU funds could be dispersed quickly on projects that could help create jobs.

Europe’s leaders had gathered under mounting pressure to soften their tough-love approach to the weaker economies among them. With Greece locked in political chaos, much bigger Spain has warned it can’t keep afloat without help. And stock markets around the world are swooning over fears the leaders won’t have the political will to act.

European leaders are facing multiple fires: political uncertainty in Greece that could see it renege on commitments made to secure rescue loans, rising borrowing costs in Spain and Italy that could force them to seek bailouts, and sluggish growth across the region exacerbated by budget cuts meant to reassure markets about high debt levels.

“What we need is a decisive plan for Greece, and we need decisive plans to help get the European economies moving,” British Prime Minister David Cameron said earlier as he headed into the summit.

“But if we’re not going to keep coming back and back to meetings like this, we also need to deal with some of the longer-term issues at the heart of running a successful single currency, having a bank that gets behind that single currency, having coherent long-term plans to make sure that single currency is coherent,” he said.

Leaders have said that everything must be on the table, including a discussion about whether the 17 countries that use the euro should spread the risk and borrow money jointly — issuing so-called “Eurobonds.” This would mean every country could borrow funds at the same rate, substantially lowering the costs for the more indebted countries.

But expectations have been low for agreement on concrete measures to boost growth and stability in the eurozone. Europe’s main stock indexes plunged more than 2 percent Wednesday, and the euro fell 0.8 percent to $1.2561, its lowest level in nearly two years.

On Tuesday, the Organization for Economic Cooperation and Development became the latest body to warn that the eurozone is at risk of falling into a “severe recession” and suggest that it slow the pace of austerity, or cost-cutting measures, in some countries.

That’s exactly what many in Greece are asking for. The country has undertaken massive spending cuts and tax hikes to slash its deficit and rein in its debt — and in exchange for the bailout loans that help keep it paying the bills. But Greece is now in its fifth year of recession, and many argue the country cannot hope for a recovery if it sticks to the deal.

In a recent election, neither of Greece’s two main parties, both of which support the bailout deal, fared well. Instead, minor parties that are threatening to renege on those commitments saw their popularity surge. A new round of elections is set for June 17.

It is now a question of who will blink first. If the Greeks pick an anti-bailout government and renege on the terms of the bailout, the country could be forced into a messy exit of the euro. That could irreparably fracture the common currency and rattle global financial markets.

Some European countries are already hinting that Greece should be given better terms. Both the International Monetary Fund and the Organization for Economic Cooperation and Development have said the pace of austerity measures should be slowed in some countries to reduce the risk of severe recession.

European Union leaders are nonetheless presenting a united front and leaving it up to the Greek people to decide their future in Europe.

“Greece has to make an important choice on June 16, and their choice has to be European,” Hollande, the French president, said as he headed into Wednesday’s meeting. “France wants that the Greeks stay in the eurozone, and the Greeks must respect their commitments. At the same time, the eurozone must show it supports Greece.”

Wednesday’s discussions were held to set up a another summit in late June.

Slow growth and uncertainty over Greece are making things worse for other struggling eurozone countries, like Spain, whose borrowing rates are high — and rising — because of fears that its government finances might be overwhelmed by the costs of rescuing its ailing banking sector.

In a meeting early Wednesday with Hollande, Spanish Prime Minister Mariano Rajoy warned that his country couldn’t continue much longer with its current high borrowing rates. The high rates are at the heart of Europe’s crisis and are what caused Greece, Ireland and Portugal to seek bailouts.

“Europe has to come up with an answer,” Rajoy said in Paris. “It is a must, because we cannot go on like this for a long time, with large differences when it comes to financing ourselves.”