Wednesday's assassination attempt on Slovak Prime Minister Robert Fico was premeditated and politically motivated, Slovak government officials told a press conference on Thursday, adding the suspect acted alone.

"This is a lone wolf whose actions were accelerated after the presidential election since he was dissatisfied with its outcome," Interior Minister Matus Sutaj Estok told reporters. 

Police have charged the suspect, a 71-year-old male, with suspected murder. Estok said the suspect did not belong to any radical political party and had taken part in anti-government protests since last year.

Fico was shot Wednesday afternoon after attending a government meeting in the town of Handlova, some 150 km northeast of the capital Bratislava. He remains in serious condition.

"Unfortunately, I cannot say yet that we are winning (the battle to save Fico) or that the prognosis is positive because the extent of the injuries caused by four gunshot wounds is so extensive that the body's response will still be very difficult," Deputy Prime Minister Robert Kalinak told Thursday's press conference. 

The shooting was the first major assassination attempt on a European political leader in more than 20 years and spurred international condemnation, with political analysts and lawmakers saying it was indicative of an increasingly febrile and polarized political climate across the continent.

(With input from agencies)