U.S. President Donald Trump said Monday that Iran was "collapsing" as Washington prepared to announce the details of a new economic pressure campaign that Tehran has derided as an admission of defeat.

Almost six months into their war, the two sides are locked in a stalemate, with peace talks stalled, Iran keeping the key Strait of Hormuz shut and Washington persisting with a naval counter-blockade of Iran.

Iran’s Foreign Ministry spokesperson on Monday warned that Tehran would respond harshly to expanded U.S. sanctions, including measures against countries it sees as cooperating with Washington.

“Any escalation of this situation will undoubtedly bring about consequences,” Esmail Baghaei said. “Our hands are not tied.”

The Palestinian American homeowner whose residence was besieged earlier this month by Israeli settlers said on Monday that he remained unable to move freely in the West Bank village of Qusra. Loui Ridi traveled from Ohio to the Israeli-occupied West Bank to join his relatives defending his home from Israeli settlers a week ago.

Palestinians whose homes have been besieged can only now move about following prior authorization from the Israeli military, which declared the area a closed zone to restore order in Qusra and converted a nearby home into a makeshift drone base.

Syrian Foreign Minister Asaad al-Shibani met over the weekend with a high-level Israeli delegation in Jordan to try to defuse tensions after Israel last week struck an air base in northern Syria, Syrian state news agency SANA reported Monday.

The U.S.-mediated discussions on Sunday focused on restarting negotiations for a future security agreement between the two countries, SANA said.

Iran's currency hit a record low Monday as Washington prepared to announce new sanctions it said would be an "economic D-Day" and would add further pressure on an economy already battered by previous sanctions and a U.S. naval blockade.

The rial dropped to 2.02 million to the U.S. dollar as trading opened on informal currency markets. Iran's official Central Bank rate stood at around 1.5 million rial to the dollar, but the informal rate is what most Iranians pay.

A Syrian court on Monday handed a life sentence to Ahmad Hassoun, the country's former grand mufti under ousted leader Bashar al-Assad, convicting him of crimes including inciting sectarian strife and exploiting his position.

Hassoun, the 10th Assad-era figure to be sentenced under the new authorities, was Syria's top Muslim cleric for 16 years, known for his close ties to the former president and frequent appearances alongside him on religious occasions.

A tanker caught fire after being struck by an "unknown projectile" off the Red Sea coast of Saudi Arabia on Monday, a British maritime agency said.

"The Company Security Officer reported a tanker has been struck by unknown projectile causing a fire to the vessel on the main deck. All crew are safe and accounted for and no environmental impact has been reported," said the United Kingdom Maritime Trade Operations (UKMTO).

The U.S. special envoy to Syria and ambassador to Turkey on Sunday walked back his comments from two days ago that Israel "still" occupies the Golan Heights in violation of U.N. resolutions, remarks that went against U.S. President Donald Trump 's position on the disputed territory.

Israel captured the Golan Heights from Syria in the 1967 Mideast war and annexed it in 1981. The United Nations and most of the international community consider the territory occupied Syrian land and do not recognize Israel's annexation of it.

Israel carried out a fresh strike in Syria and lambasted U.S. envoy Tom Barrack for criticizing an earlier attack on an air base in the northwest, which Israel has accused Turkey of seeking to use.

U.S. envoy for Syria Tom Barrack on Tuesday slammed Israel's attack on the disused military air base that day as an "unnecessary escalation that does not advance regional stability".

Iran has warned countries against participating in the United States' "economic war" against the Islamic republic, saying they would be considered enemies.