The region has been on edge since Moscow annexed the Crimean peninsula from Ukraine last year and offered alleged military support for pro-Russian separatists battling Kiev government forces in eastern Ukraine.

The 70-year-old Berzins, who announced his decision in a video on his webpage, was never wildly popular since he beat incumbent Valdis Zatlers in July 2011.

It is the 100-seat parliament, not voters, that chooses the president via a secret ballot. Political horse trading is expected to run rampant to secure the simple majority required for a candidate to win.

Parliament is expected to vote on the new head of state in late May or early June.

Only former banker and basketball star Martins Bondars has confirmed his desire to run, but coming from the small Regional Alliance party he is not regarded as a strong candidate.

Undeclared frontrunners being mulled by local media are MEP Sandra Kalniete from the same Unity political party as Prime Minister Laimdota Straujuma, European Court of Justice judge Egils Levits and Marcis Auzins, current rector of the University of Latvia.