By Daina Beth Solomon and Ted Hesson

MEXICO CITY U.S. border authorities encountered more than 142,000 migrants at the U.S.-Mexico border in the first half of September, according to data shared by Mexico's president, a tally on pace to match or even surpass previous monthly highs.

Mexican President Andres Manuel Lopez Obrador shared the U.S. Customs and Border Protection (CBP) figures during a morning press conference and proposed a visit to Washington in November to discuss migration and other issues.

The number of migrants caught crossing illegally or presenting themselves at legal border crossings has steadily risen after dropping in mid-May when the U.S. rolled out stricter new asylum rules.

The increase has strained U.S. cities at the border and further north. The mayor of Eagle Pass, Texas, declared a state of emergency on Tuesday due to a "severe undocumented immigrant surge" into the city as several thousand migrants reportedly arrived in recent days.

U.S. President Joe Biden, a Democrat, has grappled with record numbers of migrants attempting to cross illegally since he took office in 2021 and is already facing attacks over the issue as he runs for reelection in 2024. Republicans blame Biden for reversing hardline immigration policies of Republican former President Donald Trump, the frontrunner for his party's nomination.

The Biden administration on Wednesday announced that it would grant nearly half a million Venezuelans already in the U.S. access to work permits following demands by Democratic state and city officials to help migrants work legally.

To reduce illegal crossings, the Biden administration rolled out a new regulation in May that requires migrants to schedule an appointment to enter at a legal border crossing or face a higher standard for asylum. The administration also has opened other legal ways for migrants to enter the U.S. from abroad.

(Reporting by Daina Solomon in Mexico City and Ted Hesson in Washington; Editing by Mica Rosenberg, Aurora Ellis and Daniel Wallis)