Since the 2011 overthrow of Moamer Kadhafi, Libya has lacked a national government, which has made it the main gateway for African migrants heading for the 28-member EU on dangerous Mediterranean crossings.
Merkel, who faces elections in September, has been under intense pressure to reduce the number of asylum seekers coming to Germany, which has taken in over one million migrants since 2015.
Her government has urged the Maghreb states and Egypt to step up border controls and speed up repatriations of migrants whose asylum applications are rejected.
Merkel first heads to Egypt, where she will meet President Abdel Fattah al-Sisi, before holding talks on Friday with Tunisian President Beji Caid Essebsi.
She is joined by a business delegation that could sweeten the diplomacy with investments badly needed by both countries, which are grappling with sluggish economies, tourism slumps after internal turmoil and jihadist attacks, and high unemployment, especially among youths.
A major focus in Egypt and Tunisia will be on their troubled neighbour Libya, a largely lawless country that has porous desert borders with Algeria, Niger, Chad and Sudan.
"Without a political stabilisation of Libya, we won't be able to stop the human traffickers operating out of Libya who are responsible for by far the most arrivals in Italy," Merkel said in her latest weekly podcast.
"Egypt, as a regional institution, as a regional power, plays a major role here, as do Algeria and Tunisia."
The trip is part of a larger diplomatic push by Merkel, who last year visited Mali, Niger and Ethiopia. She had also planned a trip to Algeria last week, but it was called off after President Abdelaziz Bouteflika fell ill.
Germany, which this year holds the G20 presidency, has also announced investment partnerships in Africa with the long-term goals of reducing poverty and deterring people from leaving in the first place.
Last year, Berlin spearheaded an EU agreement with Ankara that helped sharply reduce the influx of migrants through Turkey and western Balkan countries.
But as with the Turkey deal, the negotiations with the North African countries have been clouded by human rights concerns.
In particular, an idea floated by Merkel's interior minister - for North African countries to build holding centres for returned migrants - has been rejected by Merkel's centre-left coalition partners and by rights groups.
Foreign Minister Sigmar Gabriel - whose Social Democrats hope to topple Merkel this year - dismissed the idea, saying "I doubt that all this has been really thought through".
Human Rights Watch noted that Egypt had largely "banned protests, imprisoned tens of thousands of people, often after unfair trials, and outlawed the country's largest opposition group, the Muslim Brotherhood."
"Ensuring safe and swift returns of Tunisians and Egyptians who are not in need of protection is legitimate, as long as the procedures are fair," said Judith Sunderland, a Europe and Central Asia director for the group.
"It's another thing entirely to pursue dodgy deals that could trap asylum seekers and migrants from elsewhere in countries like Tunisia and Egypt that cannot guarantee decent treatment or meaningful access to asylum."
But Merkel is under huge pressure at home to achieve results in an election year, as the anti-immigration Alternative for Germany party hopes to enter the national parliament for the first time.
Public fears in Germany have been heightened by several jihadist attacks last year -- especially the truck rampage at a Berlin Christmas market on December 19 that killed 12, an attack attributed to a Tunisian immigrant, Anis Amri.
Anger had previously been fanned on New Year's Eve of 2015-16, when large groups of mostly North African men sexually assaulted and robbed hundreds of women in the western city of Cologne.