Tehran has urged the international community to confront Washington's demands, while the United States warned Iran anew that it will have a "very bad time" if a peace deal is not reached soon.

In a letter to Pope Leo XIV, Iran's President Masoud Pezeshkian said the "destructive approach" of the US and Israel and their "illegitimate attacks" are not directed solely against Iran, but rather against the rule of law on the global level, international law, human values, and the teachings of divine religions, the Tehran Times reported.

"It is evident that the costs of such a dangerous approach will be borne by the entire international community," Pezeshkian said.

"Therefore, the international community is expected to adopt a realistic and fair approach and to confront the unlawful demands and the adventurous and dangerous policies of the United States," he said.

Similarly, Iranian Foreign Minister Abbas Araghchi said on X that the US-Israeli war against Iran is also affecting US households, which are absorbing rising costs. This situation "was all avoidable", he said.

US President Donald Trump renewed his warning on Saturday that Tehran would face "a very bad time" if it failed to reach an agreement with Washington.

In an interview with French television channel BFMTV, Trump said he had no idea whether Iran would sign an agreement. "They had better make a deal," he said.

Iran's Fars News Agency reported on Sunday that Washington had presented a five-point list that included a demand for Iran to keep only one nuclear site in operation and transfer its stockpile of highly enriched uranium to the US.

The US also refused to release "even 25 percent" of Iran's frozen assets abroad or pay any reparations for the damage inflicted on Iran during the war.

The semiofficial Mehr News Agency said, "The United States, offering no tangible concessions, wants to obtain concessions that it failed to obtain during the war, which will lead to an impasse in the negotiations."

Meanwhile, the US Treasury Department ended a temporary waiver on Russian oil sanctions after its expiration on Saturday, cutting off a monthlong exemption for global buyers to purchase Russian crude stranded at sea, Al Jazeera reported.

The shift is likely to push global energy benchmarks upward and increase gasoline prices in the US, which are already averaging $4.50 a gallon ($1.19 per liter), Al Jazeera reported.

On Sunday, Qatar's Prime Minister and Foreign Minister Sheikh Mohammed bin Abdulrahman bin Jassim Al Thani held a phone call with Saudi Arabia's foreign minister, Prince Faisal bin Farhan Al Saud.

The two leaders discussed regional developments, particularly those related to the US-Iran ceasefire and the efforts aimed at de-escalation that contribute to enhancing security and stability in the region.

In the UAE, a drone strike triggered a fire at an external power generator outside the core security zone of Barakah Nuclear Power Plant in Abu Dhabi on Sunday, Abu Dhabi's media office said.

No casualties have been reported, and authorities confirmed the blaze has not affected radiological safety.

Regarding the Strait of Hormuz, Iran introduced a new mechanism to manage traffic over the critical waterway, which has seen a slight increase in ships transiting through in recent days.

"In this process, only commercial vessels and parties cooperating with Iran will benefit from it," said Ebrahim Azizi, chairman of the Iranian Parliament's National Security and Foreign Policy Committee. "The necessary fees will be collected for the specialized services provided under this mechanism."