During the first part of the route. through the Laptev Sea. the vessels had to sail in up to two meters thick very close drift ice.

Opponents claim sanctions unfairly penalize US firms while allowing their foreign rivals such as Royal Dutch Shell and BP to operate in Russia.

Lukoil. Russia'.s second-biggest oil producer. has increased output by 29.000 bpd.

OPEC agreed with Russia and other oil-producing allies last month to raise output from July.

In recent months. Egypt introduced its latest wave of price hikes for fuel. drinking water and electricity.

Saudi Arabia and several other members of OPEC have increased exports sharply ahead of sanctions on Iran.

Sechin said last month he was satisfied with oil prices rising to $70-$80 per barrel.

CNPC has now a 30 percent stake. while Iranian company PetroPars holds the remaining 19.9 percent.

GDP growth forecast at 1.9 per cent in 2018 following Opec meeting in June.

US officials have called on buyers of Iran'.s crude oil to end imports from the country as of November.