The man charged with shooting and seriously wounding Slovakia's prime minister said he did so to oppose the government's Ukraine policy but regrets his actions, according to a court document.

Slovakia was left reeling last week after the head of government, Robert Fico, was struck by four bullets while greeting supporters in the central town of Handlova.

He was rushed to hospital and underwent two lengthy operations in nearby Banska Bystrica. The hospital on Thursday said that he remains in a "serious but stable" condition.

The alleged gunman, identified by Slovak media as 71-year-old poet Juraj Cintula, has been charged with premeditated attempted murder and was remanded in custody at a hearing on Saturday.

"During the interrogation, he stated that since he does not agree with the policy of the current government... he decided to act," pretrial judge Roman Puchovsky wrote in a decision on Saturday.

The accused notably said he disagreed with the government's decision to abolish the special prosecutor's office and to stop sending military aid to Ukraine, as well as alleged media persecution.

"He repeated that he did not want to kill (name redacted) but wanted to wound him and impair his health, that he aimed at his lower torso," Puchovsky wrote.

"He realises that he acted completely impermissibly, that he should not have harmed the victim," the judge added.

"He sincerely regrets his actions."

The attempted assassination has highlighted acute political divisions in Slovakia, where 59-year-old Fico took office in October after his Smer party won a general election.

Now serving his fourth term as prime minister, Fico soured ties with Ukraine after he questioned the neighbouring country's sovereignty as it battles Russian forces. (AFP)