New Spanish Foreign Affairs Minister Alfonso Maria Dastis Quecedo, left is welcomed by the E.U. High Representative for Foreign Affairs Federica Mogherini last week in Brussels. EPA/OLIVIER HOSLET (Olivier Hoslet/EPA)

Perplexed foreign ministers from the European Union nations met Sunday to try to assess the election of Donald Trump as U.S. president, underlining the uncertainty for America’s closest allies over issues as wide-ranging as Iran, Russia and climate change.

The emergency dinner gathering was a measure of how suddenly the U.S.-Europe relationship has been cast into disarray by the election of a man most European leaders openly campaigned against. The E.U. is deeply dependent on U.S. cooperation for a host of European priorities, many of which Trump called into question on the campaign trail. Even the most fundamental issue appears to be in flux: American guarantees for Europe’s security that have underpinned Western relations since World War II.

Diplomats from some of Europe’s most powerful countries say they have little basis to judge how Trump will govern or what his priorities will be upon taking over the White House. Unlike most conventional campaigns, which maintain basic outreach to the embassies of U.S. partners ahead of the election, Trump’s advisers spurned E.U. diplomats’ efforts to meet, leaving foreign leaders grasping for information.

The European Union nations will be partners with the United States “based on our own values, principles, interests,” E.U. foreign policy chief Federica Mogherini said after the dinner. But she said that she was preparing the 28-nation bloc to stand more on its own on defense and security matters. She said she had pushed for “the need to strengthen European unity around some key issues that will be even more crucial in the months to come.”

Before the election, E.U. foreign and defense ministers had already been scheduled to meet Monday and Tuesday, but the Sunday evening dinner was added after the unexpected result. Not all E.U. foreign ministers attended; those of Britain and France questioned whether a U.S. election was truly a crisis. Hungary’s anti-immigration government has welcomed the Trump victory.

It is clear that Trump will reverse many of the foreign policy priorities of the Obama administration, but the extent and the details remain unclear after a campaign marked by shifting pronouncements and sometimes-contradictory statements by Trump and his allies.

“We are going to see the positions of the new American administration in the coming months,” said Belgian Foreign Minister Didier Reynders, who said his counterparts were still trying to understand what to expect from the change in power. “We are going to do everything to be in contact with the transition team.”

Trump has denounced the July 2015 deal aimed at restricting Iran’s ability to produce nuclear weapons, for example, but it is not clear whether he would abandon it altogether or seek to renegotiate elements of it. Congressional Republicans have also opposed the deal.

A shift could lead to Iran’s full-scale resumption of its nuclear program, but it is unlikely that European nations would agree to reimpose the economic restrictions on Tehran that were lifted in exchange for agreeing to the deal.

Nor is it clear whether Trump intends to abandon U.S. sanctions against Russia for its actions in Ukraine. Europe has been able to maintain unity on its own anti-Kremlin sanctions in part because of U.S. pressure, so a shift in Washington could give balky countries such as Italy and Hungary fresh license to object to renewal of the measures.

Trump has also called into question the need for NATO, the Western military alliance that has recently beefed up its presence in Eastern European member countries that are nervous about Russia. European and NATO leaders have pointed out that the single time NATO nations came to the defense of a member nation under attack was on behalf of the United States following Sept. 11, 2001. They say that if the White House goes in a different direction, American interests would also suffer.

“Rather than deepening our differences, we need to nurture what unites us,” wrote NATO Secretary General Jens Stoltenberg in Britain’s Sunday Observer newspaper. “Going it alone is not an option, either for Europe or for the United States.”

The sudden electoral shift in Washington is also pushing European leaders to talk about doing more for themselves both on defense and on soft-power issues that traditionally have been shared between the allies on either side of the Atlantic. Some E.U. leaders have discussed the need to unite themselves as a force that could rival U.S. influence in the world — a plea that many acknowledge behind closed doors as more wishful thinking than concrete policy.

Though the U.S. election was Sunday’s focus, the day also brought to power Kremlin-friendly leaders in Bulgaria and Moldova, in a broader shift for Russia’s global prospects.

In Bulgaria, the former commander of the nation’s air force, Rumen Radev, was far outpacing his opponent in presidential elections. Radev wants to maintain his country’s place in NATO but wants to improve ties to Moscow. Bulgaria is a member of the E.U. and NATO but has long been pulled culturally between the West and Russia. The election threw the country into political chaos, with pro-E.U. prime minister Boyko Borisov announcing his resignation after the result.

In Moldova, pro-Kremlin presidential candidate Igor Dodon also won his election on Sunday. Speaking in Russian after the results were announced, he promised to steer his country toward Russia after years of competing tugs between Brussels and Moscow. Russia maintains a military force in Moldova’s breakaway Transnistria region.