Libya's National Oil Corp. (NOC) on July 12 accused the United Arab Emirates (UAE) of instructing eastern forces in Libya's civil war to reimpose a blockade of oil exports after the departure of a first tanker in six months.

The UAE, along with Russia and Egypt, supports the eastern-based Libyan National Army (LNA) of Khalifa Haftar, which on July 11 said the blockade would continue despite it having let a tanker load with oil from storage.

"NOC has been informed that the instructions to shut down production were given to [the LNA] by the United Arab Emirates," it said in a statement, resuming force majeure on all oil exports.

There was no immediate comment on NOC's accusation from either the LNA or the UAE.

Haftar has been on the back foot after Turkish support helped the internationally recognized Government of National Accord (GNA) turn back his 14-month assault on the capital Tripoli.

After the GNA gained ground, NOC also tried to restart production at the Sharara oil field but said this effort was quickly shut down and accused Russian mercenaries fighting alongside the LNA of deploying there.

On Friday the Vitol tanker Kriti Bastion docked and loaded at Es Sider port before sailing on Saturday, the first legal export of Libyan oil since the blockade was imposed in January. NOC said Russian and Syrian mercenaries fighting alongside the LNA now occupied Es Sider.

Under international agreements, only NOC can produce and export oil and revenues must flow into the Central Bank of Libya. Both those institutions are based in Tripoli, seat of the GNA.

The LNA said on July 11 it would keep up the blockade until a list of conditions were met, including channeling oil revenue into a new bank account based outside the country to then be distributed regionally.

On July 12, the United States' Libya embassy said the resumption of the blockade came after "days of intense diplomatic activity" to let NOC resume output, and said it "regrets that foreign-backed efforts" had impeded this.