The study, published on Thursday, found that slightly more than one million Mexicans and their families left the US for Mexico between 2009 and 2014.

During the same time frame, some 870,000 Mexicans moved to the US, resulting in a net flow to Mexico of 140,000. The overall flow of Mexican immigrants between the States and Mexico is currently at its lowest since the 1990s, the study found.

Pew's Director of Hispanic Research, Mark Hugo Lopez, said that the era of mass migration from Mexico is "at an end."

Family at the forefront

Pew found that the main motive for the move to Mexico was the desire to either reunite families or begin one. Other reasons included the slow recovery of the US economy in the wake of the recession, as well as stricter enforcement of US immigration laws at the US-Mexican border. Mexico's ageing population also means that there is less competition for young people looking for work in Mexico.

A similar study by Pew in 2012 found the net migration to be near zero. The latest results therefore reflect a significant turning point in one of the US' largest mass migrations.

Long time coming

Between 1965 and 2015, more than 16 million Mexicans moved to the US - more than any other country. The number of Mexican immigrants in the US peaked in 2007 at 12.8 million.

"This is something we've seen coming," Lopez said, adding that migration from Mexico to the US has been slowing down over the last decade.

The study's findings counter reports of an out-of-control situation at the US-Mexican border, which triggered Republican presidential candidate Donald Trump to demand that Mexico finance a 3,145-kilometer (1,954-mile) fence along the entire length of the border.

ksb/bw (Reuters, AP)