Tehran, Iran - The speaker of Iran's parliament accused the US on Sunday of plotting a ground attack despite publicly pushing for a negotiated deal, after a US warship with around 3,500 military personnel arrived in the Middle East.

Mohammad Bagher Ghalibaf's comments come after more than a month of aerial bombardments by Iran, US, and Israeli forces, and as key regional players met to hold talks in Pakistan.

The war has escalated into a regional conflagration as Iran has retaliated with attacks on Gulf states, sending energy markets into a tailspin and threatening the world economy.

"The enemy publicly sends messages of negotiation and dialogue while secretly planning a ground attack," Ghalibaf said in a statement carried by the official IRNA news agency.

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"Our men are waiting for the arrival of the American soldiers on the ground to set them on fire and punish their regional allies once and for all," he added.

The USS Tripoli, an amphibious assault ship carrying around 3,500 Marines and sailors, arrived in the Middle East on Friday.

The Washington Post reported the Pentagon was preparing plans for weeks of ground operations – potentially including raids on sites near the Strait of Hormuz – though US President Donald Trump has yet to officially approve any ground deployment.

Iran says it has effectively blocked the Strait of Hormuz, a vital shipping lane which previously accounted for a quarter of the world's seaborne oil trade, to hostile shipping.

Trump has repeatedly spoken of diplomatic contacts with Iran, although these claims have been denied by Tehran.

Pakistan, acting as a go-between for Washington and Tehran, hosted foreign ministers from Saudi Arabia, Turkey, and Egypt in Islamabad for talks on the crisis.

The four-way meeting between the top diplomats of the Muslim nations was slated to discuss "a range of issues, including efforts to de-escalate tensions in the region," Pakistan's foreign ministry has said.