The State Border Service of Ukraine will begin a trial run of the biometric control system at the Hoptivka checkpoint in Kharkiv region and the Bachivsk checkpoint in Sumy region as early as on December 27, and the system will enter into full effect on January 1, 2018, as planned, the assistant of the service's head, Oleh Slobodian, told Interfax-Ukraine on Wednesday.

"We will start the trial run at the two checkpoints today. However, the system will be launched on the border and at international airports on Monday, as planned," Slobodian said.

The State Border Service has made and posted videos instructing foreign citizens on how they should use the system upon arrival in Ukraine.

The system of biometric control for citizens of 71 countries which may pose threats to Ukrainians and Ukraine's national security will be put into place at 157 international and interstate checkpoints on January 1, 2018, Slobodian said on his Facebook page.

In turn, the Ukrainian Interior Ministry reported the enforcement of biometric control for passengers arriving by train.

"Biometric control has been enacted in rail transport. Once you pass this brief and pleasant procedure you will be in Ukraine," the ministry said on Twitter on Wednesday.