While the two countries share the island of Hispaniola, they are worlds apart in terms of development.
Crime-plagued Haiti is one of the poorest nations in the Americas while the Dominican Republic, a popular Caribbean tourist destination, has prospered in recent decades amid marked political stability.
Many Haitians cross the border clandestinely in search of work in the fields or in the construction industry in the Dominican Republic.
"The benefit for both nations will be of great importance," said Dominican President Luis Abinader shortly before pushing the button to begin pouring concrete into the foundations of what will be the wall in the province of Dajabon, some 230 kilometres northwest of the capital.
About 500,000 Haitians and tens of thousands of their descendants live in the Dominican Republic, a Spanish-speaking nation of about 11 million people, according to the most recent immigration survey conducted in 2018.
Abinader estimates the border wall will reduce the smuggling of commercial goods, weapons and help fight organised crime in both nations.
He started the project, which aims to build a 164-kilometre wall, ahead of the anniversary of the Dominican Republic's independence from Haiti on February 27, 1844.
Abinader says the first phase of the project will be completed within nine months at the latest.
The 20-centimetre-thick concrete wall topped by a metal mesh will be 3.9 metres high and will have fibre optics for communications, movement sensors, cameras, radars and drones.
The project also includes the construction of 70 watchtowers and 41 access gates for patrolling.
