CUCUTA, Colombia (REUTERS) - Colombia has strengthened immigration controls and will give aid to hundreds of thousands of Venezuelans fleeing an economic crisis, President Juan Manuel Santos said on Thursday (Feb 8), as his country spends millions of dollars to support the migrants.

The number of Venezuelans living in Colombia increased 62 percent in the last half of 2017 to more than 550,000, the migration authority has said. Many arrive in utter poverty, forced to sleep in doorways and under bridges while they try to scrape together enough money to feed their children.

Santos said he would put in place stricter migratory controls along the Venezuelan border, temporarily suspending new daily entry cards for Venezuelans and deploying 2,120 more soldiers along the shared frontier.

Speaking in Cucuta, a border city of about 670,000 Colombian inhabitants, Santos said he would not tolerate crime committed by Venezuelan migrants and would prosecute any unlawful behavior.

He will create a new registry of Venezuelans already in Colombia and open a center with the United Nations to provide humanitarian aid.

Colombia estimates it costs US$5 a day to supply each Venezuelan migrant with food and lodging.

The government did not provide figures on how many migrants it was supporting.