No leaders from Morocco or Mauritania were present at the meeting, set to take place every three months.
The coalition is aimed at furthering "security, stability and development throughout the region," Tunisian foreign minister Nabil Ammar read from a statement.
The meeting was decided on by Algerian President Abdelmajid Tebboune, Libya's head of presidential council Mohamed Al-Menfi and Tunisian President Kais Saied when they met at an energy summit in Algeria last month.
"This consultation must not be limited to political issues only, but rather include all areas of economic and social developments for the peoples of the three countries," Ammar read from the statement.
When the meeting was announced last week, Moroccan media outlets said it had been part of Algeria's aim to form a "Maghreb alliance" against Morocco, its regional foe.
Algerian President Tebboune had said earlier this month that the creation of the coalition was "not directed against any other state" and that the door was open to "our neighbor in the west," referring to Morocco.
His diplomacy chief, Ahmed Attaf, had also defended the initiative, saying it would fill the void left by the Arab Maghreb Union (UMA), founded in 1989 in Morocco.
The UMA was created with the aim of bringing the region's countries closer and furthering their shared political and economic interests.
But growing tensions between Algeria and Morocco sent the organization into a tailspin, particularly over disputed Western Sahara.
The two countries cut diplomatic ties in 2021 after Morocco's normalization deal with Israel.
The meeting Monday also pointed out the "danger of foreign interference in the Sahel and the Sahara desert," the statement said.
In a visit to Morocco the same day, French Interior Minister Gerald Darmanin lauded the kingdom's help in fighting terrorism and its cooperation in the Sahel region, where France was forced to withdraw troops in 2022 and last year after military coups in Mali, Niger and Burkina Faso.
Monday's meeting called for an "absolute rejection to foreign interference in Libyan affairs," Ammar said in his statement, as well as "elections that safeguard Libyan unity and its territorial safety."
It also pledged to "protect shared borders from the dangers and impacts of irregular migration among other organised crime."
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