Türkiye and its neighbor Bulgaria will continue increasing the fight against migrant smuggling, Turkish Interior Minister Süleyman Soylu has pledged.

"We have been working together for a long time, especially on migrant smuggling, human trafficking, drug smuggling and border security to stop and prevent the migration flow," Soylu told a news conference with his Bulgarian counterpart, Ivan Demerdzhiev, in Istanbul on Sunday.

He explained that he and his Bulgarian counterpart came together to bring to life decisions made at a meeting between Turkish President Recep Tayyip Erdoğan and Bulgarian President Rumen Radev in Istanbul on Dec. 9.

The same week, a shared mechanism established between the two neighbors went operational, stipulating many measures for their shared border, including technological transformations and capacity increases at the Kapıkule and Hamzabeyli border gates.

"In this respect, we have an agreement in place to exchange information and continue the same efforts without let up," Soylu said on Sunday.

He revealed that the two countries agreed on terms about completing a joint training agreement for their security forces, and added that optic towers were erected along the Bulgaria border route with the Turkish side initiating work on a new physical system at the border.

"As Mr. Erdoğan has expressed at the meetings, Kapıkule is the world’s second biggest gate in terms of crossings and trade. Therein, Türkiye’s output and exports increase, and border crossings as well as commercial transits at Kapıkule are vital for both us and Bulgaria," Soylu noted.

He went on to thank Demerdzhiev for his efforts in extraditing criminals to Türkiye, referring to the latest ruling at a Bulgarian court earlier this week for the return of Mustafa Levent Göktaş, a former soldier implicated in a 2002 murder associated with the Gülenist Terror Group (FETÖ), the shadowy organization behind the defeated 2016 coup in Türkiye.

"I would like to reaffirm that our cooperation against terrorist groups, including the PKK, YPG/PKK and FETÖ continues resolutely," he noted.

For his part, Demerdzhiev thanked Soylu for providing "great support" to neighboring Bulgaria in its struggle to curb "the migrant pressure," and said the European Union also lauded this cooperation as the two countries protect the EU's external borders.

"I am confident that the EU will take steps to further support these great efforts of both countries," he said.

He added that the countries were also planning to construct a railway and highway for improved transport between Kapıkule and Hamzabeyli.

"Additionally, we discussed the concrete steps we will take against terrorist organizations active on both sides. Cooperation in the fight against terrorist groups will continue," Demerdzhiev said while ensuring Bulgaria will arrest terrorists and hand them over for justice.

The PKK is listed as a terrorist organization by Türkiye, the European Union, and the U.S., and is responsible for the deaths of 40,000 people, including women, children and infants. It has been waging a bloody terrorist campaign against Türkiye for four decades, attacking both security personnel and civilians. The YPG is the PKK's Syrian terrorist branch.

FETÖ and its U.S.-based leader Fetullah Gülen orchestrated the defeated coup in Türkiye on July 15, 2016, in which 251 people were killed and 2,734 wounded. Ankara also accuses FETÖ of being behind a long-running campaign to overthrow the state through the infiltration of Turkish institutions, particularly the military, police and judiciary.