US CIA chief John Ratcliffe has taken a secret trip to Russia, sparking concerns of a hidden agenda. What was the purpose of his visit and what does it mean for relations between Moscow and Washington?

Ratcliffe's surprise visit to Russia has raised eyebrows in both countries. The CIA chief met with Russian intelligence officials, including his opposite number in Russia's overseas spy agency, Sergei Naryshkin. For related coverage, explore our detailed analysis on Technology and Digital Systems.

A Warning or a Provocation?

One US official told Politico that the meeting was primarily to warn Russia against any escalatory action against the Baltic states.

The situation in Ukraine is becoming increasingly dire. The country has been under attack from long-range drones, which have hammered Russia's energy industry and brought the war home to ordinary Russians.

Long queues for petrol and billowing smoke coming from stricken oil refineries are a stark reminder of the human cost of this conflict.

A Tense Situation in Ukraine

Russia has several options on the table, including escalating its ballistic missile attacks on Ukraine or expanding its undeclared 'hybrid war' against Nato countries.

It could also consider a low-key attack on Lithuania, which would not trigger Nato's mutual self-defence clause and might prompt the US to intervene.

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Another possibility is Russia using its tactical nuclear warheads as an integral part of its order of battle. This option has long been considered taboo

Despite the speculation, the true purpose of Ratcliffe's visit remains unclear. Was he trying to persuade Russia to end its military cooperation with Iran or negotiate a prisoner swap?

Only time will tell what this sudden CIA dash to Moscow was really about.

That could be trying to persuade Russia to end its military cooperation with Iran, for example, or maybe about more prisoner swaps or the prospect of a mass mobilisation of Russian troops.

But make no mistake, this trip was highly unusual and it came at a time of rising tension between Moscow and the West.

Ratcliffe was taken to Moscow in a US military plane President Donald Trump stated John Ratcliffe's trip to Russia was a "semi-routine" visit but there is nothing routine about the CIA chief making a secret, 10,000-mile return dash to Moscow.