In a letter to Secretary of State Mike Pompeo, Senate Foreign Relations Committee Chairman Robert Menendez called for an investigation into the discovery of US weapons in Libya and demanded clarification on arms agreements with the UAE by July 15.

The invitation comes after reports that the UAE delivered US-made missiles to the troops of retired brigade Khalifa Hafter in Libya.

Following the takeover of the city of Gharyan (south-west of the capital) by Hafar's forces, the forces of the Wefaq government announced that they had found US and Chinese weapons, including the US-developed Javelin missiles, in a city camp.

In his letter to the Secretary of State, Menendez said: "You certainly know that if these allegations are proven, you may have to legally abolish all arms sales to the UAE."

Menendez also warned that arms sales would constitute a "serious violation" of US law and "almost certainly" a violation of the United Nations arms embargo on Libya.

Menendez said in his letter that the alleged transfer of arms to Libya was "particularly worrisome" because it came after the administration of President Donald Trump was in Congress and approved a $ 8.1 billion arms sale to Saudi Arabia and the UAE.

The New York Times reported on Friday that forces of the internationally recognized Accord government had discovered four Jafflin missiles at a base used by Hafitar fighters in Gharyan.

The newspaper said the writing on US-made missiles indicates that it was sold to the UAE in 2008.

The newspaper also reported that investigations have begun in the US Department of State and Defense on the arrival of sophisticated US weapons to Haftar.

Investigations were focused on whether Haftar's acquisition of four sophisticated US anti-tank missiles violates US laws and UN arms embargoes to the parties to the conflict in Libya, officials in both ministries said.

The newspaper said a spokeswoman for the US Defense Department and the UAE ambassador in Washington, Yusuf al-Otaiba, declined to comment on the matter.

The State Department also reported earlier that it had taken reports of abuse of US weapons in Libya very seriously and was seeking answers.