Bulgarian Prime Minister Boyko Borisov on Thursday ruled out that the construction of Struma motorway can completely go around Kresna Gorge, in southwestern Bulgaria.

He told private bTV station the road can be split in two where it approaches the gorge so those traveling in the direction of the capital Sofia could use a bypass route.

The Prime Minister, however, made clear the lanes leading out of Bulgaria would have to go through Kresna Gorge, arguing the terrain would not allow to relocate the entire motorway.

"We cannot put a motorway up on the mountain peaks. This can work about one lane, but not about six," he said, but vowed that the government would commit itself to preserving biodiversity.

"We want to preserve little snakes, turtles, little frogs and the people who live there. We want to think about how to combine nature and people."

His comments came less than a day after reports emerged that he had sided with environmentalists calling for an alternative route.

A section of the motorway is to cross the gorge area, with its construction officially kicking off earlier this week.

Environmentalists have been calling on authorities to adopt an alternative route to avoid bringing harm on the diverse wildlife in the area. The government, however, insists construction is to be sped up to avoid loss in EU funding which is also used to build Struma motorway. According to Regional Development Minister Lilyana Pavlova, Bulgaria will lose BGN 736 M in funding and will have to reimburse Brussels with some BGN 500 M if the motorway is not complete by 2023.  

On Friday morning, mountaineer and zoologist Boyan Petrov and environmental activist Andrey Kovachev once again opposed the plans to built any motorway infrastructure in the area of Kresna Gorge, urging the government to find an alternative route without placing any lanes within the gorge.

The two were injured in a car crash not far from the gorge last week while counting dead animals smashed by vehicles that use the existing road.

"After [the crash]... I am even more determined there should be no [section of the Struma] highway there," Petrov told NOVA earlier this week.

On Friday he and Kovachev reiterated their warning that some species were being left extinct by human activity in the gorge.

They insisted that the number of animals hit by vehicles in Kresna Gorge has seen a tenfold increase over ten years.

Kovachev warned the move to build Struma in time would not spare Bulgaria an infringement procedure for breach of environmental rules.

He called on authorities to explore all remaining options that would help bypass the gorge, including the construction of a 15-km tunnel.