President Donald Trump says he has instructed the Department of Homeland Security to turn migrants arriving at the US-Mexico border in a caravan away.

Mr Trump, in a series of two tweets, announced that he had told DHS to do so, and added that he believes the United States is being taken advantage of by individuals attempting to enter the country as refugees, and that he is considering using the North American Free Trade Agreement (Nafta) as a bargaining chip to force Mexico to take care of the migrants before they even get to the US.

“Despite the Democrat inspired laws on Sanctuary Cities and he Border being so bad and one sided, I have instructed the Secretary of Homeland Security not to let these large Caravans of people into our country,” one of Mr Trump’s tweets reads. “It is a disgrace. We are the only Country in the World so naive! WALL”.

The president followed that with his musing about using Nafta to pressure Mexico.

“Mexico, whose laws on immigration are very tough, must stop people from going through Mexico and into the US. We may make this a condition of the new Nafta Agreement. Our Country cannot accept what is happening!” Mr Trump wrote. “Also, we must get Wall funding fast”.

Mexico’s top diplomat, Luis Videgaray, rebuffed the president Monday for his suggestion that trade and immigration should be linked issues.

People strike across America for A Day Without Immigrants Show all 16 1 /16 People strike across America for A Day Without Immigrants People strike across America for A Day Without Immigrants Demonstrators march during the "Day Without Immigrants" protest in Chicago, Illinois, February 16, 2017. Theopolis Waters/Reuters People strike across America for A Day Without Immigrants Demonstrators march during the "Day Without Immigrants" protest in Washington, DC, U.S., February 16, 2017. Aaron P. Bernstein/Reuters People strike across America for A Day Without Immigrants Protesters march in the streets outside the Texas State Capital on 'A Day Without Immigrants' February 16, 2017 in Austin, Texas. The crowd, which grew to well over a thousand participants, marched from the Austin City Hall to the Texas State Capital. Across the country hundreds of restaurants and eateries are closing for the day to protest President Trump's immigration policies and to highlight the contributions of immigrants to U.S. business and life. Drew Anthony Smith/Getty People strike across America for A Day Without Immigrants Protesters march in the streets outside the Texas State Capital on 'A Day Without Immigrants' February 16, 2017 in Austin, Texas. Drew Anthony Smith/Getty People strike across America for A Day Without Immigrants AUSTIN, TX - FEBRUARY 16: Protesters march in the streets outside the Texas State Capital on 'A Day Without Immigrants' February 16, 2017 in Austin, Texas. Drew Anthony Smith/Getty People strike across America for A Day Without Immigrants Demonstrators march during the "Day Without Immigrants" protest in Chicago, Illinois, February 16, 2017. Theopolis Waters/Reuters People strike across America for A Day Without Immigrants Demonstrators march during the "Day Without Immigrants" protest in Chicago, Illinois, February 16, 2017. Aaron P. Bernstein/Reuters People strike across America for A Day Without Immigrants Protesters march in the streets outside the Texas State Capital on 'A Day Without Immigrants' February 16, 2017 in Austin, Texas. The crowd, which grew to well over a thousand participants, marched from the Austin City Hall to the Texas State Capital. Across the country hundreds of restaurants and eateries are closing for the day to protest President Trump's immigration policies and to highlight the contributions of immigrants to U.S. business and life. Drew Anthony Smith/Getty People strike across America for A Day Without Immigrants Protesters march in the streets outside the Texas State Capital on 'A Day Without Immigrants' February 16, 2017 in Austin, Texas. Drew Anthony Smith/Getty People strike across America for A Day Without Immigrants Protesters march in the streets outside the Texas State Capital on 'A Day Without Immigrants' February 16, 2017 in Austin, Texas. Drew Anthony Smith/Getty People strike across America for A Day Without Immigrants Protesters march in the streets outside the Texas State Capital on 'A Day Without Immigrants' February 16, 2017 in Austin, Texas. Drew Anthony Smith/Getty People strike across America for A Day Without Immigrants Protesters march in the streets outside the Texas State Capital on 'A Day Without Immigrants' February 16, 2017 in Austin, Texas. Drew Anthony Smith/Getty People strike across America for A Day Without Immigrants Protesters march in the streets outside the Texas State Capital on 'A Day Without Immigrants' February 16, 2017 in Austin, Texas. Drew Anthony Smith/Getty People strike across America for A Day Without Immigrants Protesters march in the streets outside the Texas State Capital on 'A Day Without Immigrants' February 16, 2017 in Austin, Texas. The crowd, which grew to well over a thousand participants marched from the Austin City Hall to the Texas State Capital. Across the country hundreds of restaurants and eateries are closing for the day to protest President Trump's immigration policies and to highlight the contributions of immigrants to U.S. business and life. Drew Anthony Smith/Getty People strike across America for A Day Without Immigrants High school student Kathia Suarez holds up a sign as she protests with others outside the Grayson County courthouse in downtown Sherman, Texas, Thursday, Feb. 16, 2017. LM Otero/AP People strike across America for A Day Without Immigrants High school senior Vicky Sosa holds a sign outside the Grayson County courthouse in downtown Sherman, Texas, Thursday, Feb. 16, 2017. In an action called "A Day Without Immigrants," immigrants across the country are expected to stay home from school, work and close businesses to show how critical they are to the U.S. economy and way of life. LM Otero/AP

“Mexico decides its migratory policy in a sovereign way, and migratory cooperation with the United States happens because it’s in Mexico’s interest,” Mr Videgaray said in a tweet.

“It would be unacceptable to condition the renegotiation of Nafta to migratory actions outside this frame of cooperation,” he said.

Mr Trump first began talking about the migrant caravan weeks ago, when a group of about 1,200 people first convened at Mexico’s southern border.

At the time, Mr Trump attempted to force Mexico to deal with the group of people itself, and later said that the caravan had dissolved.

The group has thinned out quite a bit since then, but a considerable group is still headed to the US, where many say they plan on submitting themselves to authorities and ask for asylum.

Organizers for the group say that there are roughly 600 people left, and some have begun arriving at the border.