WASHINGTON (AP) — Some of President Donald Trump’s top foreign policy priorities stand at pivotal moments as two high-level national security officials head to an annual security forum in Germany. Strains in the trans-Atlantic relationship have cast doubt on whether they can count on much help from European leaders in advancing Trump’s agenda.

Secretary of State Mike Pompeo and Defense Secretary Mark Esper’s visit to Munich comes as the U.S. appears close to signing a truce in Afghanistan, is pushing for renewing sanctions on Iran, has introduced a new Israeli-Palestinian peace plan and is trying to discourage allies from allowing the Chinese company Huawei to be part of next-generation wireless networks.

Meanwhile, in the background are worries about the global spread of the deadly new coronavirus from China.

The Munich conference, which opens Friday, attracts a wide array of foreign diplomats and national security officials and has been the venue for unexpected and sometimes surprising revelations. It has been marked by turbulent U.S.-European relations before, notably during the debate over the Iraq war in early 2003. But the current level of tension exceeds that of previous years and spans a wider range of issues.

Europe is unlikely to play a major role in what could be the biggest highlight: Pompeo and Esper are to meet Afghan President Ashraf Ghani on the sidelines of the conference on Friday amid strong indications that a seven-day “reduction in violence” agreement that would lead to formal negotiations between Afghanistan’s factions and is close and likely imminent. A proposal is “on the table,” Esper told reporters Wednesday in Brussels.

Trump has agreed in principle to the deal, the final details of which are being hammered out by U.S. special envoy for Afghanistan Zalmay Khalilzad and Taliban representatives in Doha, Qatar. People familiar with the plan’s outlines say it calls for the successful conclusion of the weeklong truce to be followed within 10 days by the start of all-Afghan negotiations to set the road map for the country’s political future.

U.S. officials have brushed aside claims that a Taliban ultimatum forced their hand. And, they noted that despite his campaign pledge to withdraw American troops from Afghanistan and elsewhere, Trump has nixed previous deals that appeared close in response to attacks on U.S. forces.

While Afghanistan has the potential to be the most significant development in Munich, others issues are more likely to highlight tensions with Europe — notably the future of the 2015 Iran nuclear deal.

Pompeo, who has as many as 10 separate meetings with foreign officials and a speech crammed into his two-day visit, will arrive in Munich shortly after the State Department gave the clearest signal yet that the administration will deliver an ultimatum to its European allies on ending the accord.

The administration has been frustrated by the reluctance of Britain, France and Germany to move forward quickly with a process that could lead to the re-imposition of U.N. sanctions on Iran for violating the terms of the agreement. Iran has breached several limits on program imposed by the deal but maintains it is only responding to U.S. violations. Trump withdrew the United States from the deal.

The Europeans, who want to salvage the deal, have invoked a dispute resolution mechanism designed to resolve the issues or refer them to the U.N. Security Council, but U.S. officials aren’t pleased with what they see as a lack of urgency in a process that can take months to complete.

Its patience nearing an end ahead of the October expiration of a U.N. arms embargo on Iran, the administration has laid out a path for it to keep the ban in place by forcing action in the Security Council.

In a document provided to Congress this week, the State Department said for the first time that the conditions for the automatic re-imposition, or “snapback,” of U.N. sanctions lifted under the terms of the deal can be determined by any of the states that negotiated it.

The administration has already advanced the argument, advocated by Iran hawks, that despite Trump’s withdrawal, the U.S. remains a “participant” in the deal as defined by the Security Council resolution that enshrined it.

The Europeans, not to mention Russia and China, have scoffed at that position but may not have any choice but to accept it as the resolution does not permit a veto on snapback. And, if the U.S. position is rejected by others it would create a major geo-political confrontation over sanctions that would pose serious risks to international commerce.

But the administration has now taken that a step further, arguing that the U.S. has the authority to determine if Iran is in “significant non-performance” with the deal’s requirements. It says that because the criteria for significant non-performance are not spelled out in the U.N. resolution they can be defined broadly by any participant.

“We assess that the state initiating the snapback mechanism retains flexibility in interpreting what constitutes ‘significant non-performance,'” the State Department said in a written response to a question on the matter from Sen. Ted Cruz, a Texas Republican and a leading Iran hawk in Congress.

The Europeans have resisted previous lobbying to join the U.S. in leaving the deal, but the administration is expected to push them harder in advocating for an extension of the arms embargo if they want to save it.

Beyond the differences over Iran, the U.S. is facing serious pushback from Europe on Trump’s Middle East peace plan, which is widely seen as biased in favor of Israel at the expense of the Palestinians and inconsistent with previous guidelines for a settlement to the conflict.

On Tuesday, the European Union members of the Security Council — Belgium, Estonia, France and Germany— gave the plan the cold shoulder. “The U.S. initiative, as presented on 28 January, departs from these internationally agreed parameters,” they said in a statement.

Pompeo and Esper also face an uphill battle in trying to prevent European countries from allowing the Chinese tech giant Huawei to play a role in their advanced 5G wireless networks. Despite dire warnings that a Huawei presence would compromise information security and threats that the U.S. could limit intelligence cooperation with countries in which the company operates, several nations have rejected an outright ban.

Britain, notably, announced last month that it would allow Huawei to participate in certain non-sensitive areas of its networks, and European Union 5G guidelines fall far short of addressing U.S. concerns.