Vladimir Putin, Russia’s prime minister, moved to quash a diplomatic rift with Belarus on Monday after a dispute over milk imports threatened to harm relations between the former Soviet neighbours, The Financial Times reported.

Tension between the two countries erupted over the weekend when Alexander Lukashenko, Belarusian leader, pulled out of a regional security summit in Moscow at the last minute.

Dmitry Medvedev, the Russian president, accused Mr Lukashenko of failing to act “as a true partner” after he said Moscow’s ban on Belarusian milk exports “effectively forces Belarusians to their knees”.

But on Monday Mr Putin told ministers, who had complained Mr Lukashenko was “over-politicising” the milk war, to be “more careful” in their statements. “Whatever happens, we are one family with Belarus. There can be all kinds of arguments and scandals in a family, but life takes its course and we need to work,” he said.

The outbreak of tension highlights the difficulties facing Moscow as it vies with the EU to cement its influence over former Soviet states and forge new economic and security ties.

A report published on Tuesday warns the European Union to increase its political and economic support for its eastern neighbours, including Belarus, or “face a ring of failing states and an increasingly active Russia rebuilding its sphere of influence”.

The European Council for Foreign Relations, a London-based think-tank, argues that the EU’s recently launched eastern partnership policy for the six countries – Belarus, Ukraine, Moldova, Georgia, Armenia and Azerbaijan – is not sufficiently dynamic as a response to the region’s political and economic crises. The authors call for country-specific support policies, including an urgent visa liberalisation.

Mr Lukashenko had been due to attend a regional security summit where participants, including Armenia, Kazakhstan and Kyrgyzstan, signed an agreement to create a regional rapid reaction security force to deal with terrorism and regional conflicts.

Mr Lukashenko said Belarus’ absence meant the agreement had no legal force.

The spat between Minsk and Moscow broke out just days after Mr Putin led a drive to agree a new customs union with Belarus and Kazakhstan, dropping Russia’s 16-year unilateral bid to join the World Trade Organisation in favour of a joint bid. The move was seen by analysts as part of Russia’s focus on building a regional power base.

Experts said Mr Putin would seek to keep a lid on the differences between Russia and Belarus as the customs union became a central goal.

“I believe the conflict will ease,” said Fyodor Lukyanov, editor of Russia in Global Affairs. “Russia will undertake all efforts to make sure the customs union goes through.”

The Financial Times