Senior United States and Iranian officials have said that they could be close to a breakthrough in talks to strike a draft deal, while remaining cautious about the chances of ending the war in the Middle East.

US President Donald Trump told CBS in a phone interview that the two sides were “getting a lot closer” to a deal, but also warned that if they do not reach an agreement “we’re going to have a situation where no country will ever be hit as hard as they’re about to be hit”.

Iran said gaps remained between the parties, and the dispute over its nuclear programme would not be part of the initial talks, but that it was finalising a 14-point framework for a deal.

In a sign of the uncertainty surrounding the outcome of the talks, Trump also told another US news outlet, Axios, that the chances of a deal were a “solid 50/50”.

Iranian Foreign Ministry spokesman Esmaeil Baqaei noted what he called “a trend towards rapprochement” but said “it does not necessarily mean that we and the United States will reach an agreement on the important issues”.

He added: “Our intention was first to draft a memorandum of understanding, a kind of framework agreement composed of 14 clauses.”

He said that he hoped the details of a final agreement could be worked out “within a reasonable timeframe between 30 to 60 days” after the framework is finalised.

US Secretary of State Marco Rubio also expressed optimism, as Pakistan’s Army chief - a key go-between between the US and Iran - left Tehran after two days of talks with senior Iranian leaders.

Rubio said: “There is a chance that, whether it’s later today, tomorrow, in a couple days, we may have something to say”.

Iran’s chief negotiator Mohammad Bagher Ghalibaf had warned earlier that Washington would face a tough response if it resumed hostilities, after US media reports raised the prospect of new strikes and Iranian officials accused the US side of making “excessive demands”.

Ghalibaf posted on social media: “Our armed forces have rebuilt themselves during the ceasefire period in such a way that if Trump commits another act of folly and restarts the war, it will certainly be more crushing and bitter for the United States than on the first day of the war”.

On another front in the war, Lebanese state media said Israel struck the country’s south, as fighting has not stopped despite an April 17 ceasefire.

Lebanon’s military said one strike targeted a Lebanese Army barracks in the south and wounded a soldier.

Hezbollah drew Lebanon into the war on March 2 with rocket fire at Israel after US-Israeli strikes killed Iran’s Supreme Leader.

Hezbollah said that its chief Naim Qassem had received a message from Iran indicating that it “will not give up its support” for the Lebanese group.

- AFP