Central American migrants, who are part of a caravan of migrants trying to reach the United States, hitchhike on a truck along the highway as they continue their journey in Tapachula, Mexico Oct. 22, 2018. (Xinhua/REUTERS)

UNITED NATIONS, Oct. 22 (Xinhua) -- UN Secretary-General Antonio Guterres has been calling on Central American leaders to cooperate with the world organization in handling more than 7,000 migrant caravan people heading toward the Mexico-U.S. border, a UN spokesman said on Monday.

"The secretary-general has been in touch with different leaders over the weekend," Farhan Haq, Guterres' deputy spokesman, told reporters at a regular briefing.

"The thing he has been stressing is the need for the leaders to be working with the International Organization for Migration, IOM, and the UN Refugee Agency, UNHCR," said Haq.

"He believes that the situation needs to be dealt with in line with international law and with full respect for countries' rights to manage their own borders," he said.

"The states in the region need to cooperate on resolving the situation. At this point both IOM and UNHCR are dealing with different countries on the ground to assist in this matter," he said.

The spokesman noted that 7,233 people are marching toward the Mexico-U.S. border.

When asked about the threat from U.S. President Donald Trump to close the southern border of the United States, Haq replied: "Obviously we believe that there needs to be full respect for countries' rights to manage their own borders. At the same time the situation needs to be dealt with in line with international law and the states in the region need to cooperate on resolving the situation."

Haq said those were the ground rules to deal with this matter.

He said the UN refugee agency already has sent reinforcements to bolster its capacity in Mexico and the number is expected to increase in the following days.

Published reports said the migrants are fleeing widespread violence, poverty and corruption in Honduras through Guatemala and Mexico to the U.S. border.

What is unusual about this trek of thousands of men, women and children is that it largely began spontaneously by word of mouth as opposed to Trump's accusations it was funded by members of the Democratic Party and was largely made up of criminals.