Iran will soon hand a counter-proposal for a nuclear deal to the United States via Oman, Iranian foreign ministry spokesperson Esmaeil Baghaei said on Monday, in response to a US offer that Tehran deems “unacceptable”.

The spokesperson also called on the international community to force nuclear disarmament upon Israel, Iran’s longstanding foe which Tehran says is trying to thwart the nuclear negotiations.

“The US proposal is not acceptable to us. It was not the result of previous rounds of negotiations. We will present our own proposal to the other side via Oman after it is finalised. This proposal is reasonable, logical, and balanced,” Baghaei said.

“We must ensure before the lifting of sanctions that Iran will effectively benefit economically and that its banking and trade relations with other countries will return to normal.”

Reuters previously reported that Tehran was drafting a negative response to the US proposal which was presented in late May.

An Iranian diplomat said the US offer failed to resolve differences over uranium enrichment on Iranian soil, the shipment abroad of Iran’s entire stockpile of highly enriched uranium and reliable steps to lift US sanctions.

Baghaei said there was not yet any detail on the timing of a sixth round of nuclear talks between Tehran and Washington.

Last week, Supreme Leader Ayatollah Ali Khamenei dismissed the US proposal as against Iran’s interests, pledging to continue enrichment on Iranian soil, which Western powers view as a potential pathway to building nuclear weapons. Iran says its nuclear programme is only for peaceful purposes.

During his first term in 2018, US President Donald Trump ditched a 2015 nuclear pact between Iran and six powers and reimposed sanctions that have crippled Iran's economy. Iran responded by escalating enrichment far beyond that pact’s limits.

Iran says the West has turned a blind eye to Israel’s nuclear programme even while pushing against Iran's. Israel neither confirms nor denies that it has nuclear weapons.

Israeli naval forces boarded and seized a charity vessel trying to break a naval blockade of the war-torn Gaza Strip on Monday.

Baghaei said sensitive Israeli documents, which Iran has previously promised to unveil, would demonstrate “that parties constantly questioning Iran’s peaceful nuclear programme actively work to strengthen Israel’s military nuclear programme”.

The negotiating parties should not allow Israel to disrupt diplomatic processes, he added.