Sweden will begin construction on a new nuclear reactor before the country's next legislative election in 2026, Prime Minister Ulf Kristersson said in an interview published on Friday.

His right-wing coalition government, propped up by the far-right Sweden Democrats, has vowed to massively ramp up nuclear energy in Sweden but a formal decision on the type of reactor to be built has yet to be taken.

The government said in November 2023 it wanted to increase nuclear power production equivalent to two nuclear reactors by 2035, with a "massive expansion" to follow by 2045.

State-owned utility Vattenfall is in the process of conducting a feasibility study on the construction of at least two small modular reactors (SMRs) at the Ringhals nuclear power station in the southwest of the country.

It aims to put the first one into commission in the first half of the 2030s.

It has begun acquiring land in the area but has not yet applied for environmental permits.

Asked by daily Dagens Nyheter if construction would begin before the next general election, Kristersson replied: "Yes, it will."

"The decisions required to build new nuclear power will have been taken. And hopefully that will be combined with a physical spade in the ground," he said.

"We are totally committed. If we are going to succeed at electrification then we need to double electricity production, and nuclear power is an integral part of that."

SMRs are advanced nuclear reactors that have a power capacity of up to 300 megawatts of electricity per unit, which is about one-third of the generating capacity of a traditional nuclear power reactor.

They are relatively simple to build, as their systems and components can be factory-assembled and transported as a unit to a location for installation, which also makes them more affordable than large power reactors.

Sweden currently has six reactors at three nuclear power plants, which generated about 30 percent of the electricity used in the country.