WASHINGTON — The White House announced Wednesday that Swiss President Ueli Maurer will arrive in Washington Thursday for an unscheduled meeting with President Donald Trump, to possibly discuss U.S. relations with Iran.

Switzerland has in the past played the role of mediator between the United States and Iran. Analysts in Washington suggested that the unannounced meeting will focus on mounting tensions between Iran and the Americans. It is unusual for a head of state to arrive at the White House without prior notice.

>> Analysis: Iran is choosing the time and place to confront America

Over the weekend, several news outlets reported that the Trump administration has asked Switzerland to send messages on its behalf to Iran, as previous U.S. administrations have done in the past.

According to the reports, the Swiss government provided the Iranian leadership with a phone number through which they could directly reach some of Trump's closest associates. Trump said last week that he wants Iran to “call me.”

Maurer and Trump are expected to meet in the late morning. The White House said that “the two leaders will discuss the partnership between the United States and Switzerland, including matters such as Switzerland’s role in facilitating diplomatic relations and other international issues.”

Meanwhile, the Washington Post reported Wednesday that Trump prefers a diplomatic approach and wishes to stand by his pledge to avoid costly wars, worrying that his top advisers — including National Security Adviser John Bolton — could rush him into a confrontation with the Islamic Republic.

According to officials quoted by the Post, Trump is frustrated with what he considers to be warlike planning and is uncomfortable with talk of regime change. Sources said Trump wouldn't be inclined to respond with force unless Iran made a “big move.”

The Post added that officials said the view that deterrence rather than conflict was required was “monolithic” across the Pentagon. It said this view was shared by civilian officials, including by acting-Defense Secretary Patrick Shanahan, who Trump nominated last week to remain in the job, pending Senate approval.

Secretary of State Mike Pompeo made a surprise visit to Baghdad earlier this month after U.S. intelligence showed Iran-backed Shi’ite militias positioning rockets near bases housing U.S. forces, according to two Iraqi security sources.

According to the Post, Pompeo’s visit intended to relay U.S. alarm over the recent intelligence on Iran, in addition to Washington’s desire for diplomacy instead of war.