An additional number of border police officers will be sent to the border between Bulgaria and Turkey amid reports of an increased migratory pressure, officials say.

The Interior Ministry on Saturday reported a twofold surge in the number of people who attempted to cross into Bulgaria for the first two weeks of August compared to the same period of July.

The figure follows Bulgarian Prime Minister Boyko Borisov's interview with NOVA TV on Thursday where he voiced his concerns with a possible increase in the number of migrants who are left trapped in Bulgaria if Europe tightens border controls and Turkey stops implementing the deal with the EU. He subsequently held a phone conversation with his Turkish counerpart Binali Yildirim, accepting the latter's proposal for a bilateral mechanism on migration.

As many as 1858 people tried to enter Bulgaria illegally between August 1 and 12, border police chief Antonio Angelov is quoted by Focus News Agency as saying.

There have been 30 000 attempts since the year began, according to Angelov.

The development comes as 200 staff working for the EU's border agency FRONTEX are set to arrive next week to assits Bulgarian border police.