Iran said on Friday it could "easily" hit U.S. warships in the Gulf, the latest in days of saber rattling between Washington and Tehran, while its top diplomat worked to counter U.S. sanctions and salvage a nuclear deal denounced by President Donald Trump.

Tensions have risen in recent days, with concerns about a potential U.S.-Iran conflict. Earlier this week, the United States pulled some diplomatic staff from its embassy in Baghdad following weekend attacks on four oil tankers in the Gulf.

"Even our short-range missiles can easily reach (U.S.) warships in the Persian Gulf," Mohammad Saleh Jokar, the deputy for parliamentary affairs of the elite Revolutionary Guards (IRGC), was quoted by Fars news agency as saying.

"America cannot afford the costs of a new war, and the country is in a bad situation in terms of manpower and social conditions," he added.

Washington has increased economic sanctions and built up its military presence in the region, accusing Iran of threats to U.S. troops and interests. Tehran has described those steps as "psychological warfare" and a "political game."

In Washington, a senior administration official said the United States is "sitting by the phone" but has heard no message yet from Iran that it is willing to accept Trump's overtures for direct talks.

"We think they should de-escalate and come to negotiations," the official, who declined to be identified, told a small group of reporters.

Trump has urged Iran's leadership to hold talks over its nuclear program and regional influence amid rising tensions between the two countries that has fanned fears of armed conflict after the United States deployed an aircraft carrier group to the region.

Iranian army chief Major General Abdolrahim Mousavi vowed: "If the enemy miscalculates and commits a strategic error, it will receive a response which will make it regret (its action)," the semi-official news agency Mehr reported.

Foreign Minister Mohammad Javad Zarif, on a visit to Japan and China, said the international community and remaining signatories of the nuclear deal should act to save the accord as "supportive statements" are not enough.

Last week, Iran notified the five remaining signatories that it would reduce some commitments under the accord. Tehran has asked the other signatories, including Germany, Britain and France, to help protect its economy from U.S. sanctions.