The U.S. southern border has seen a sharp drop in migrant encounters entering between ports of entry at the southern border, according to a CBP source.

President Donald Trump on Monday kicked off his sweeping immigration crackdown, tasking the U.S. military with aiding border security, issuing a broad ban on asylum and taking steps to restrict citizenship for children born on U.

It followed threats by Trump to levy import taxes of 25% on Mexico and Canada, accusing them of allowing undocumented migrants and drugs to come into America. Though he did not mention the US by name, the Vice Premier of China on Tuesday said his country was looking for a "win-win" solution to trade tensions and wanted to expand its imports.