US President Donald Trump has threatened to immediately double tariffs on Mexican imports unless Mexico stops a group of more than 1,000 migrants heading north toward the United States, escalating his administration's pressure on neighbouring countries to enforce Washington's increasingly restrictive migration policies.

In an aggressive post on his Truth Social platform on Thursday, Trump demanded that Mexico prevent the migrants from continuing their journey, warning that they would not be allowed to enter the United States.

"Mexico must stop them, now, and if they do not do so, the tariffs on Mexico will be immediately doubled," Trump wrote, adding that there would be "no leniency."

The threat came after approximately 1,500 migrants, most of them from Central America, began travelling north from Tapachula in Mexico's southern state of Chiapas on Tuesday. Many are travelling with their families and children, hoping to find a safer future and better opportunities in the United States.

The group, known as "God With Us," initially plans to reach Mexico City, more than 1,000 kilometres away, to seek assistance from federal authorities and protection from detention while pursuing their journey north.

Many migrants have become stranded in Tapachula amid US entry restrictions and deportations, facing limited access to employment, healthcare and education.

Some members of the caravan have also reported surviving kidnapping and other forms of violence in Mexico, while others say returning to their home countries would put their lives at risk.

Their hopes for a more welcoming US immigration policy have grown following Democrats' victories in last week's midterm elections. However, analysts have cautioned that significant policy changes are unlikely while Trump remains in the White House.

The latest threat adds to an approach that has increasingly relied on border restrictions, deportations and pressure on neighbouring countries to contain migration before people reach US territory.

Trump said Mexican authorities, the Texas governor, US Border Patrol and Immigration and Customs Enforcement (ICE) had been informed of his warning.

Mexican security forces have also moved to block other migrant groups. On Tuesday, authorities intercepted a separate caravan of around 100 Central American migrants in Chiapas, with approximately 40 people reportedly detained.

Mexico had not immediately issued a response to Trump's latest tariff threat, according to reports.

The US president's warning risks further straining relations with Mexico by linking trade penalties to the movement of vulnerable migrants, many of whom are fleeing insecurity, violence and economic hardship.

Rather than addressing the circumstances forcing people to leave their homes, Trump's latest ultimatum places additional pressure on Mexico and threatens economic consequences for refusing to contain migration on Washington's terms. (ILKHA)