Russia’s second-largest oil group on Wednesday said that it would consider ceasing the supply of petroleum to Iran, a move that would make it the latest in a line of companies to halt shipments to Tehran.

Lukoil’s move may be a further signal that Russia’s government is beginning to throw its weight behind the drive to increase pressure on Iran over its nuclear programme. Senior officials at the company told the Financial Times they were considering halting the shipments.

Lukoil has been supplying refined petroleum to Tehran intermittently, moving between about 250,000 barrels to 500,000 barrels every other month, according to traders.

“They are not one of the major players in supplying gasoline to Iran, they do it on occasion,” a trader told Reuters on Wednesday. But he added: “Now they will stop because of pressure coming from their head office in Moscow.”

In March, Shell announced that it had stopped petroleum supplies to Iran, joining two of the world’s largest independent trading companies, Glencore and Vitol, which had taken similar decisions.

However, news agencies said Iran has maintained a robust import programme of refined oil products from the international market, buying from Malaysia’s state oil firm Petronas, Kuwait’s Independent Petroleum Group and France’s Total…