On Monday, President Donald Trump signaled growing optimism about ending the U.S.-Iran war after meeting Qatar's prime minister, even as Tehran dismissed Washington's claims of diplomatic progress.

Trump Sees 'Positive Momentum' Toward Ending Iran War

Trump said diplomatic efforts were gaining traction after his White House meeting with Qatar's Prime Minister Sheikh Mohammed bin Abdulrahman bin Jassim Al Thani, a key mediator in the conflict.

In a Truth Social post, Trump described their conversation as "excellent" and said they discussed Iran extensively.

"We are seeing positive momentum toward an end to this Conflict, and will ensure that America's interests are at all times protected," he wrote.

Speaking at a news conference, Trump suggested the conflict could conclude "fairly soon," stating Tehran was engaging with Washington and "talking very politely."

He also said Iran's military capabilities were effectively depleted and that further U.S. strikes were "quite unlikely."

However, Trump warned that American forces remained prepared to resume military operations if necessary. He noted that a third U.S. aircraft carrier was heading toward the Middle East, where two others were already deployed.

"I don't guarantee anything. But if we do have to go back in, we are locked and loaded and ready to go," he said, reiterating that Iran would never be allowed to obtain a nuclear weapon.

Iran Rejects US Claims, Security Chief Fires Back

Tehran, meanwhile, pushed back against Washington's characterization of diplomatic efforts.

Mohsen Rezaei, secretary of Iran's Supreme National Security Council and a former Islamic Revolutionary Guard Corps commander, accused the U.S. of manufacturing reports about negotiations, writing on X that Washington "flails like a desperate gambler" and urging it to "fold your hand."

"Time to SURRENDER to the seven conditions Iran has repeatedly set out," he wrote.

Iran's parliament speaker Mohammad Bagher Ghalibaf separately accused Israel of pulling Washington deeper into the conflict, warning that the U.S. and its allies faced a "dark age" unless Washington abandoned its "Israel First" approach.

Qatar's prime minister also confirmed that discussions with Trump and Vice President JD Vance focused on regional developments and advancing U.S.-Iran talks, expressing hope for an agreement that could restore peace.

Oil Prices Fall As Peace Hopes Lift Wall Street

Renewed hopes of diplomatic progress sent oil prices sharply lower, easing concerns about energy supply disruptions and inflation.

Dow futures rose 116 points, or 0.22%, to 52,614.00, while S&P 500 futures gained 6.75 points, or 0.09%, to 7,581 and Nasdaq 100 futures slipped 14.5 points, or 0.05%, to 28,000 as of 8:50 p.m. EST.

In commodities, WTI crude oil fell 1.05% to $85.94 per barrel, while Brent crude declined 0.78% to $91.85 per barrel as of 2:50 a.m. BST. Natural gas futures dropped 0.25% to $3.21 per MMBtu.

The SPDR S&P 500 ETF Trust (NYSE:SPY) rose 2.37% on Monday, while the Invesco QQQ Trust (NASDAQ:QQQ) gained 3.54% and the SPDR Dow Jones Industrial Average ETF Trust (NYSE:DIA) advanced 2.17%.

Meanwhile, the United States Oil Fund LP (NYSE:USO) fell 3.87%, while the ProShares Ultra Bloomberg Crude Oil (NASDAQ:UCO) declined 5.42%.