REFILE-Migrants rush to enter Mexico ahead of security crackdown demanded by Trump

Central American migrants eager to beat a crackdown by Mexico on its southern border with Guatemala scrambled into the country on Thursday as the government prepared to send thousands of National Guard members to plug gaps in the porous frontier. Mexico has agreed with the United States to demonstrate by late July that it can contain a surge in U.S.-bound migrants, following a threat from U.S. President Donald Trump to impose tariffs on Mexican goods if it failed to do so.