UNITED NATIONS — Foreign ministers from the five permanent members of the U.N. Security Council and Germany will meet with Iran’s top diplomat today to test the Islamic Republic’s apparent willingness to reach a deal to resolve international concerns about its nuclear program after years of defiance.

The meeting on the sidelines of the annual United Nations General Assembly is aimed at paving the way for the first round of substantive negotiations on the nuclear issue since April, probably next month. It will also mark the highest-level, direct contact between the United States and Iran in six years as Secretary of State John Kerry comes face-to-face with Iranian Foreign Minister Javad Zarif.

The United States, Britain, France, Russia, China and Germany will participate with European Union foreign policy chief Catherine Ashton serving as host of the meeting.

Encouraged by signs that new Iranian President Hasan Rouhani will adopt a more moderate stance than his hard-line predecessor but skeptical the country’s supreme leader will allow a change in course, President Barack Obama directed Kerry to lead a new outreach to explore possibilities for resolving the long-standing dispute. However, Obama and other U.S. officials have said Iran must prove its commitment with actions, not just words.

Rouhani is in New York this week, making his debut on the world stage with an address to the General Assembly and a series of other speeches, news conferences and bilateral meetings.

During his visit, Iran has shown new urgency in reviving the stalled negotiations, seeking to ease crippling international sanctions as quickly as possible. Rouhani said Wednesday that “we have nothing to hide” and Zarif said he hoped his counterparts “have the same political will as we do to start serious negotiations with a view to reaching an agreement within the shortest span of time.”

The West suspects Iran is trying to build a nuclear weapon and has imposed crippling sanctions on Tehran that have slashed its vital oil exports and severely restricted its international bank transfers. Inflation has surged and the value of the local currency has plunged.

Tehran has repeatedly denied its nuclear program is for anything other than peaceful purposes.

But since his June election, Rouhani has made clear he is seeking relief from the sanctions and has welcomed a new start in nuclear negotiations in hopes this could ease the economic pressure. He has said he has the full support of Iranian Supreme Leader Ayatollah Ali Khamenei, who has the final word on all important matters of state including the nuclear question.