Before leaving office last month, former UN chief Ban Ki-moon reportedly expressed concern to the Security Council that Iran’s supplying of weapons to the Lebanon-based terrorist group Hezbollah violates a longstanding arms embargo against the Islamic Republic.

In his second semi-annual report to the UN Security Council on the implementation of a resolution endorsing the 2015 Iran nuclear rapprochement deal, Ban noted a televised June speech by Hezbollah leader Hassan Nasrallah boasting of receiving military support from Tehran.

“[Nasrallah] stated that the budget of Hezbollah, its salaries, expenses, weapons and missiles, all came from the Islamic Republic of Iran,” Ban wrote, according to a Reuters report.

“I am very concerned by this statement, which suggests that transfers of arms and related materiel from the Islamic Republic of Iran to Hezbollah may have been undertaken contrary [to a Security Council resolution],” he said.

While most international sanctions against Iran were lifted under the 2015 nuclear deal, Tehran remains subject to longstanding UN and Western embargoes on conventional weapons.

Women wave a Lebanese national flag and Hezbollah flags in front of portraits of Iran's supreme leader Ayatollah Ali Khamenei (R) and Hezbollah leader Hassan Nasrallah, in the southern Lebanese town of Bint Jbeil on August 13, 2016, during a commemoration marking the tenth anniversary of the end of the war between Hezbollah and Israel. (AFP PHOTO / MAHMOUD ZAYYAT)

Women wave Lebanese and Hezbollah flags in front of portraits of Iran’s supreme leader Ayatollah Ali Khamenei (R) and Hezbollah leader Hassan Nasrallah, in the southern Lebanese town of Bint Jbeil on August 13, 2016. (AFP PHOTO / MAHMOUD ZAYYAT)

But despite the possible violation, Ban said Iran continues to uphold the tenants of the nuclear accord.

“Since 16 January 2016, I have not received any report on the supply, sale, transfer or export to the Islamic Republic of Iran of nuclear-related items undertaken contrary to the (resolution),” the outgoing secretary-general said.

Ban also noted an accusation by the French government that one of its vessels in the Indian Ocean intercepted a shipment of Iranian weapons bound for Somalia or Yemen last year.

The report to the Security Council will be discussed by the 15-member body later in January. Ban left office at the end of 2016 and Antonio Guterres has since taken over as UN chief.

In his first report on the deal’s implementation last year, Ban called on Iran to stop conducting ballistic missile launches, but stopped short of saying the launches were a violation of the UN Security Council resolution.

The 2015 Security Council resolution that authorized measures leading to the end of UN sanctions includes a provision that would automatically reinstate sanctions if Tehran reneges on its promises to abide by the agreement.