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.

Gold and silver prices dived Friday and European stock markets ended the week up while Wall Street pulled back with investors reassured by U.S. President Donald Trump's pick to take over as head of the Federal Reserve.

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.

Palestinian militant group Hamas called on Friday for Israel to reopen Gaza's Rafah crossing to Egypt immediately in both directions.

In a statement, the group called for the "immediate transition to the second phase" of the U.S.-brokered truce in Gaza, namely its provision for the reopening of Rafah, as well as the entry of a technocratic Palestinian committee to administer the territory.

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.

Iran's President Masoud Pezeshkian said on Friday that the success of diplomacy with the United States hinged on ending threating conduct after Washington's heavy military deployments in the Gulf.

"The success of any diplomatic initiative depends on the goodwill of the parties involved and the abandonment of belligerent and threatening actions in the region," said Pezeshkian in a call with his Turkish counterpart Recep Tayyip Erdogan, according to a statement by the Iranian presidency.

Iran's top diplomat Abbas Araghchi landed in Istanbul on Friday for talks where Turkey was to offer help to mediate tensions with the United States, which has mooted a possible military strike.

Turkey Foreign Minister Hakan Fidan urged Washington to resist Israeli pressure to launch a military strike on Iran, warning it would cause "great harm" to a fragile region.