Hungarian prisoners have finished building the first part of a second anti-migrant fence on Hungary's southern border with Serbia, the country's state television reported on Monday.
Prime Minister Viktor Orban announced the plans for a second fence line in August to reinforce the existing barrier erected last year along the 175-kilometer-long (110-mile-long) border.
The risk that the European Union's deal earlier this year with Turkey to stem the flow of migrants might not last means Hungary needs to strengthen its border defenses, Hungarian Prime Minister Viktor Orban said.
Orban has emerged as the standard-bearer of those opposed to German Chancellor Angela Merkel's "open-door" policy, in the wake of Europe's worst migration crisis since World War II.
Dubbed a "smart fence" by local media due to its high-tech features, construction by prisoners of the three-meter-high (10-feet) and 10.3-kilometer-long (6.4 mile-long) barrier began a month ago.
The new fence is equipped with heat and movement sensors, as well as night cameras installed at regular intervals, according to media reports.
When fully built it is expected to cut the numbers of troops and police officers required to patrol the border, said the M1 public television news channel.
The Hungarian government will decide later on when the rest of the fence line will be built, said the channel.
In late 2015, Hungary built fences along its borders with Serbia and Croatia to stem the massive tide of migrants. Other countries in the Balkans then followed suit.
Orban's government last September erected a fence topped with razor wire along the border with non-EU member Serbia, diverting the well-trodden Balkan migrant route northwards to Croatia. A month later, the border with Croatia was sealed off in similar fashion.
In 2015 over 400,000 migrants trekked through Hungary, a border of the EU's passport-free Schengen zone, toward northern Europe.
After the first fence line was completed in September last year, and another one along the Croatian border a month later, the number of migrants entering Hungary slowed to a trickle.
Orban failed in his attempt earlier this month to push through constitutional amendments to oppose any future plan by the European Union to resettle asylum seekers among members of the bloc.
The parliamentary ballot followed a divisive referendum on Oct. 2, in which 3.3 million voters backed Orban's rejection of the European Union's troubled refugee quota plan. The ballot, however, was deemed invalid due to low turnout in the nation of nearly 10 million people.
The Orban government also sued at the European Court of Justice because of the EU's 2015 decision to relocate 160,000 asylum seekers from overburdened Greece and Italy. Under the original plan, 1,294 asylum seekers would be moved to Hungary.