A senior official in Tehran has warned that intelligence reports suggest that “Iran’s enemies” ⁠are planning to occupy an Iranian island with support ‌from an unnamed country in the region.

⁠Iran’s ⁠parliament speaker, Mohammad Bagher Ghalibaf, said on Wednesday that any such attempt would be met with targeted attacks on the “vital infrastructure” of the regional country – which he did not name – that assists in the operation.

“Iranian forces are monitoring ⁠enemy movements, and ⁠if they take any step, we will ⁠attack vital ⁠infrastructure in ⁠that regional country in continuous and relentless attacks,” ‌Ghalibaf said in two separate posts on social media.

Ghalibaf’s warning comes as United States President Donald Trump continued to claim that the US was in negotiations with Iran to end the war – which Tehran has denied – while the White House also conveyed new threats against the Iranian leadership.

White House Press Secretary Karoline Leavitt said on Wednesday that Iran must accept defeat.

“If Iran fails to accept the reality of the current moment, if they fail to understand that they have been defeated militarily and will continue to be, President Trump will ensure they are hit harder than they have ever been hit before,” Leavitt said.

“President Trump does not bluff, and he is prepared to unleash hell,” Leavitt said.

Washington’s claims of peace talks while also threatening ever more punishing war against Iran come as the Pentagon sends thousands of airborne troops to the Gulf region, adding to two contingents of US Marines already on their way.

US media reports that approximately 2,000 soldiers from the US Army’s 82nd Airborne Division had been ordered to deploy to the region, while the first of two Marine Expeditionary Units – on board a huge ⁠amphibious assault ship – could arrive in the region in the next few days, according to reports.

‘US eye on Kharg Island’

Al Jazeera’s Mohamed Vall, reporting from Tehran, said people in Iran are well aware of the continuing buildup of US ground troops and warships in the region, and “they know what it is going to lead to”.

“So right now, they are much more certain of a continuation of this war than an end to it, and they say they are preparing for it,” Vall said.

“They also are aware of the US eye on Kharg Island,” he said, adding that some believe that the parliamentary speaker’s earlier threat to a regional country – should it help in an island invasion – was aimed at the United Arab Emirates.

“According to some people explaining what he said, he’s referring here to the United Arab Emirates, that it might be cooperating with the US and encouraging it to take Kharg Island,” Vall said.

“Iranians over the last few days have been saying that they know that if this happens, they are sure that it will be very destructive to that country, the United Arab Emirates, and also the US troops,” he said.

“Kharg is a small, exposed island that is very close to the Iranian mainland. They are threatening that if US troops land on it, that will be the thing that [Iranians] are waiting for – and that it will be very detrimental to the safety of US troops,” he added.

Iran’s semi-official Tasnim news agency cited an unnamed military source as saying on Wednesday that Iran could open a new front at the mouth of the Red Sea if military action takes place on “Iranian islands or anywhere else in our lands”.

The source told Tasnim that Iran has the capability to pose a “credible threat” in the Bab al-Mandeb Strait, ⁠which lies between Yemen and Djibouti.

Tasnim later quoted an “informed source” claiming that Yemen’s Houthi rebels, who are backed by Iran, are prepared to play a role “if there is a need to control the Bab al-Mandeb Strait to further punish the enemy”.

Trump has in recent days repeatedly claimed progress in talks with Iran, and while Tehran has rejected that any negotiations with the US are taking place, there are signs of tentative diplomatic efforts, with mediators in the region saying work is ongoing behind the scenes to relay messages between the two sides.

The US has reportedly proposed a 15-point plan to end the fighting, while an Iranian official was quoted by local media as saying that Tehran has put forward its own five conditions for hostilities to end.