Efforts to facilitate talks between the US and Iran are still ongoing, two Pakistani sources with knowledge of the discussions told Reuters on Tuesday, as US strikes on Iran intensified and President Donald Trump's deadline to unleash "hell" neared.

Iran has set preconditions for ​talks on a lasting ‌peace with the United States, a senior official ​told Reuters on Tuesday, ​including an immediate halt ⁠to strikes, guarantees ​that attacks will not be ​repeated, and compensation for damage.

"Iran will not show flexibility as long as the US demands surrender," a senior Iranian source to Reuters.

An official said ⁠that a permanent peace deal should allow Iran to demand fees ​for ​ships ⁠passing through the Strait of Hormuz, ​which would vary ​depending ⁠on the type of ship, its cargo, and ⁠prevailing ​conditions.

Pakistan's "positive and productive endeavours in Good Will and Good Office to stop the war is approaching a critical, sensitive stage...," the Iranian envoy to Islamabad wrote on X.

Ambassador Reza Amiri Moghadam's comments came amid reports that Pakistan was making hectic efforts to bring the US-Iran conflict to an end by arranging a ceasefire and following it up with detailed talks.

He ended his brief statement with muted optimism by writing: "Stay Tuned for more."

Tehran, for its part, rejected any proposal for a ceasefire, mandating that any peace plan include a complete end of hostilities.

Diplomatic talks coordinated by Pakistan and other regional countries were continuing, officials said, even as there appeared to be little agreement on what any cessation of hostilities would look like.

Even as Washington and Tehran were reviewing ceasefire plans Iranian officials reported damage to at least two bridges, railway infrastructure and a key highway on Tuesday as part of a wave of US-Israeli airstrikes on infrastructures.

President Donald Trump said on Monday that a ceasefire proposal put forth by mediators between the United States and Iran was a “significant step,” but he warned that it was “not good enough” as his deadline of Tuesday evening for a deal approached.

If Iran does not agree to reopen the Strait of Hormuz by Tuesday at 8 p.m. Eastern time, Trump has threatened to launch a massive attack targeting bridges, power plants and other civilian facilities that would, in his words, send Iran “back to the Stone Ages.”

But the President has also extended self-imposed deadlines in recent weeks, and diplomats around the world were asking whether Trump would find an off-ramp again or if he would follow through this time with what could be a gigantic conflagration.

“We have a plan, because of the power of our military, where every bridge in Iran will be decimated by 12 o’clock tomorrow night, where every power plant in Iran will be out of business, burning, exploding and never to be used again,” Trump told reporters at the White House on Monday afternoon. “I mean complete demolition by 12 o’clock.”

The second source said Iran was "walking on thin ice" and that the next three to four hours were critical for the future of dialogue.

"We are in touch with Iranians. They have lately shown flexibility that they could join the talks, but they are at the same time taking hard lines as a prerequisite for any negotiations," the Pakistani security source said.

He added that Islamabad was persuading Tehran to enter negotiations without prior conditions.

Iran's foreign ministry spokesperson said on Monday that messages are still being exchanged via mediators.

A senior Iranian source told Reuters on Tuesday that Tehran had rejected a proposal conveyed by intermediaries for a temporary ceasefire.

Talks on a lasting peace could begin only after the United States and Israel end their strikes, provide a guarantee they will not resume, and offer compensation for damages, the source said.

One of the sources, a senior security official, said Iran's overnight strike on Saudi Arabia's industrial facilities linked to US firms threatened to derail the talks.

If Saudi Arabia were to respond to the strikes, the talks would be over, the source said, adding that retaliation could also draw Pakistan into the conflict under its defence pact with Riyadh.

The mutual defence pact with Riyadh that requires the two countries to come to one another's defence in case of an attack.

Pakistan's foreign office said on Tuesday that the strikes on Saudi Arabia constitute a dangerous escalation.

"Such unwarranted aggressions have serious repercussions, to spoil the ongoing peaceful options and conducive environment," added a Pakistani army statement after top commanders met with army chief Asim Munir.ee headlines in present tense for this article

Islamabad has been working to avoid being pulled into the war, which could wreak havoc along its shared western border with Iran and roil discontent among its large Shi'ite population, the second largest in the world after Iran.

Pakistan's foreign office said in a statement on Tuesday that the strikes on Saudi Arabia constitute "a dangerous escalation that undermines regional peace and stability".