Lithuania has begun building a fence along its border with Belarus to deter third-country migrants from entering the country.
Vilnius has declared a state of emergency to address the sharp rise in migration, which it says Belarusian authorities are encouraging.
Lithuania -- which has backed and granted refuge to Belarus opposition figures -- has accused its neighbour of organising border crossings for people mainly from Iraq, the Middle East, and Africa.
The double, barbed wire fence will run 550 kilometres along the 680-kilometre border between the two countries.
Lithuanian Interior Minister Agne Bilotaite has estimated the construction of the fence could cost up to €41 million.
On Friday, Lithuanian border guards said they had arrested 37 new migrants, bringing the total number of detected illegal crossings to more than 1,500 since the beginning of the year, compared with just 81 for the whole of 2020.
The European Union has said it would support its member state, which has already set up tent camps to accommodate the growing number of migrants.
Relations between Lithuania and Belarus are tense following the disputed re-election of Belarusian President Alexander Lukashenko in August 2020.
The vote result triggered months of opposition protests and a harsh crackdown by Lukashenko’s regime, which forced many senior figures into exile. Belarusian opposition leader Sviatlana Tikhanovskaya fled to Lithuania soon after the election.
After Belarus diverted a passenger aircraft to Minsk to arrest an opposition journalist in May, the EU slapped further economic sanctions on the country.
In response, Lukashenko said his country would halt cooperation with the EU on migration and would not let his country "become a camp".
"We won’t hold anyone," he stated, "they are coming not to us but to the enlightened, warm and cozy Europe."