U.S. President Barack Obama on Monday challenged the Iranian leaders to take "immediate and meaningful steps" now to reduce tensions over its controversial nuclear program, one day prior to his departure for a visit to the Middle East.

In a statement issued to mark the Persian new year known as Nowruz, the president acknowledged that "serious and sustained effort" is needed to resolve the many differences between Iran and the United States.

"I have had no illusions about the difficulty of overcoming decades of mistrust," Obama said.

He stressed, however, that Washington and others are ready to reach a peaceful solution with Iran for the Islamic republic to clear doubts about the nature of its nuclear program and have access to peaceful nuclear energy.

"Now is the time for the Iranian government to take immediate and meaningful steps to reduce tensions and work toward an enduring, long-term settlement of the nuclear issue," the president declared.

"Whereas if the Iranian government continues down its current path, it will only further isolate Iran," he warned.

Noticeably, Obama stopped short of threatening military strikes should sanctions and diplomacy fail to stop Iran's uranium enrichment activities.

Iran reopened talks last month with the so-called P5+1 group of the United States, Britain, China, France, Russia and Germany, and will have another round of talks in early April.

Obama will head for Israel, the West Bank and Jordan on Tuesday night for a three-day visit, his first trip abroad after starting his second term in January, with Iran's nuclear program, the Syrian conflict and the Israeli-Palestinian peace process expected to top his agenda.

In an interview with an Israeli TV on Thursday, the president said it would take "over a year or so" for Iran to make a nuclear bomb, and reaffirmed his administration's pursuit of a peaceful resolution.

Israeli Prime Minister Benjamin Netanyahu has set a red line over Iran's nuclear project and has threatened time and again military strikes on Iran's nuclear sites. Endi