US President Donald Trump declared a 'national emergency' at the country's southern border on his first day in office. His decision heralds a major change in immigration policy.

According to a report by the British media outlet BBC, Trump was sworn in at the Capitol One Arena in Washington on Monday local time. After the swearing-in ceremony, he returned to the Oval Office and signed several executive orders. One of them is the declaration of a state of emergency at the southern border.

Trump said, "This is a huge decision." Through this, additional troops and manpower will be deployed to strengthen border security.

In addition, his much-discussed 'Remain in Mexico' policy will be re-enacted. Under this policy, the rule that asylum seekers will wait in Mexico instead of entering the United States will be re-introduced.

Trump also ordered a revision to the definition of citizenship by birth in the new executive order. In this context, he said, "We need reform in our citizenship policy, and this decision has been taken for that purpose."

Donald Trump took the oath of office as President of the United States for the second time in a one-term break today. He was sworn in by Supreme Court Chief Justice John Roberts. He was accompanied by Vice President J.D. Vance at the swearing-in ceremony.

Even before taking office, Trump has taken a tough stance against illegal immigrants. He announced that immigrants staying in the United States illegally will be deported to their countries and that new illegal immigration will be completely stopped.

Trump's move has the potential to lead to major changes in US immigration policy.