U.S. President Donald Trump has said he was hopeful of agreeing a deal with Iran after the country's supreme leader warned that any U.S. attack on the Islamic republic would trigger a regional war.

Following the Iranian authorities' deadly response to anti-government protests that peaked last month, Trump has threatened military action and ordered the dispatch of an aircraft carrier group to the Middle East.

Iran's supreme leader on Sunday likened recent anti-government protests to a "coup", warning that any U.S. attack on the Islamic republic following Washington's military deployments in the Middle East would trigger a regional war.

Iran's top security official said Saturday that progress had been made towards negotiations with the United States, even as the Islamic republic's army chief warned Washington against launching military strikes.

U.S. President Donald Trump on Saturday said Iran was negotiating with the United States, even as the Islamic republic's army chief warned Washington against launching military strikes.

"(Iran is) talking to us, and we'll see if we can do something, otherwise we'll see what happens...We have a big fleet heading out there," he told Fox News.

An explosion took place on Saturday at a building in the Iranian city of Bandar Abbas on the Gulf coast, state media reported, though the cause of the blast was as yet unknown.

Iranian army chief Amir Hatami on Saturday warned the United States and Israel against an attack, saying his country's forces were on high alert following Washington's heavy military deployments in the Gulf.

The political leader in line to become the Netherlands' next prime minister on Friday said concerns about U.S. President Donald Trump's territorial ambitions in Greenland were a "wake-up call" for Europe at a fraught time.

Centrist D66 leader Rob Jetten emphasized the need for stronger European cooperation to ensure security and prosperity — rather than focusing on the United States.

The U.N. atomic watchdog's board held a special session Friday to discuss risks to nuclear safety in Ukraine as concerns mount that relentless Russian attacks on its energy infrastructure pose an increasing danger of a nuclear accident.

The urgent meeting of the International Atomic Energy Agency's board of governors was held at the request of the Netherlands with support from 11 other countries, diplomats said — Belgium, Canada, France, Germany, Italy, Japan, Lithuania, Luxembourg, Portugal, Romania and the United Kingdom. Though it won't produce any binding outcome, the aim is to increase diplomatic pressure on Russia.

U.S. President Donald Trump asked Russian counterpart Vladimir Putin to halt strikes on Kyiv for a week "until February 1", the Kremlin said Friday, without mentioning when the request was made.

"I can say that President Trump did indeed make a personal request to President Putin to refrain from striking Kyiv for a week until February 1 in order to create favorable conditions for negotiations," Kremlin spokesman Dmitry Peskov said.

Teams negotiating an end to the Russian invasion of Ukraine have so far failed to find a compromise on the sticking point of control over Ukraine's Donetsk region, President Volodymyr Zelensky has said.

"So far, we have been unable to find a compromise on the territorial issue, specifically regarding part of eastern Ukraine," Zelensky told journalists including AFP in remarks made public Friday.