©Reuters

Russian President Vladimir Putin talks with Greek Prime Minister Alexis Tsipras during their meeting in Athens

Vladimir Putin, the Russian president, used a visit to Nato country Greece to warn its fellow members Romania and Poland that they could find themselves “in the crosshairs” over the siting of elements of a US missile programme.

In his strongest reaction to date on a missile programme the US maintains is protection against Iran, Mr Putin said Washington and its allies had ignored warnings of potential countersteps against a weapons system in eastern Europe that Moscow sees as a threat to itself.

“If yesterday in those areas of Romania people simply did not know what it means to be in the crosshairs, then today we will be forced to carry out certain measures to ensure our security,” Mr Putin told a news conference in Athens with Greek Prime Minister Alexis Tsipras.

“It will be the same case with Poland,” he said, though did not specify what actions Russia would take.

Mr Putin was in Greece to hold talks on energy and transport investments ahead of a celebratory visit to a 1,000-year-old Russian Orthodox monastery on the isolated peninsula of Mount Athos.

Greece’s leftwing Syriza government is keen to build stronger ties with Moscow, despite being snubbed last year when Mr Tsipras, then a newly elected prime minister, flew to Moscow seeking an emergency loan to stave off making further concessions to the EU and International Monetary Fund.

“For us, strengthening this relationship is a strategic choice for Greece,” said Mr Tsipras, who got his start in politics in the pro-Moscow Greek communist youth movement, after talks with the Russian president.

Mr Putin, making his first visit this year to an EU member state, sounded a somewhat gloomy note as he paid a call on Greek president Prokopis Pavlopoulos, saying: “These are difficult times for everyone from the point of view of the economy and international security.”

Almost 10 years have passed since Mr Putin last visited Athens on a mission to include Greece in the ill-fated South Stream project to pipe Russian natural gas across the Black Sea to Bulgaria and through the Balkans to central Europe.

Under Mr Tsipras, pipeline politics have once again become a priority in bilateral relations.

Greece is committed to joining a new Russian project known as South Stream II, even though it is already backing the TransAdriatic Pipeline, a rival project to reduce European dependence on Russian gas supplies. TAP, which started construction this month, will bring gas from Azerbaijan through Turkey, Greece and Albania to Italy.

In February Greece’s state gas utility Depa and Italy’s Edison signed a memorandum of understanding with Gazprom to develop the South Stream II to carry Russian gas from Bulgaria across northern Greece and the Ionian Sea to southern Italy.

Greek and Russian officials were holding talks on a new cross-border pipeline to link the Bulgarian and Greek gas networks, a long-stalled project planned by Depa, Edison and Bulgarian Energy Holding, the country’s state energy group.

Mr Putin wrote in an article published this week in the Greek newspaper Kathimerini that “Russia could help streamline Greek transport infrastructure”.

“We are referring to the participation of Russian business entities in the forthcoming Greek tenders for the purchase of assets of railway companies and the Thessaloniki port facilities.”

Russia’s state railways group RZD has officially expressed interest in buying the Greek railways operator TrainOSE and the rolling stock company Rosco which are due to be privatised this year. Russia’s transport minister Maksim Sokolov has recently revived a proposal for a package deal that would also include the acquisition by RZD of a majority stake in Thessaloniki port in northern Greece.

Mr Putin was flying to Thessaloniki on Saturday to join Patriarch Kyrill, the head of the Russian Orthodox church and an ally of the president, who casts himself as a believer. He was due to attend ceremonies officiated by Kyrill marking the 1,000th anniversary of the Agios Panteleimon monastery on Mount Athos, which is home to a large community of Russian monks.

The Russian president’s visit to Mount Athos marks the high point in a year of Greek-Russian religious and cultural events being held to celebrate the monastery’s anniversary.