MEXICO CITY, Sept 23 (Reuters) - Tropical Storm John is

rapidly growing and is set to become a hurricane by Monday

afternoon as it barrels toward Mexico's Pacific coast, according

to the U.S.-based National Hurricane Center (NHC).

John is set to speed up even more before it makes landfall

on Tuesday near resort destination Puerto Escondido, the NHC

forecast showed, bringing with it strong winds, a dangerous

storm surge and life-threatening flash flooding.

The NHC warned that preparations should be "rushed to

completion" to protect life and property as winds will slam the

coast Monday evening.

The coastline from Punta Maldonado to Bahias de Huatulco is

under a hurricane warning, the NHC said, with a tropical storm

warning stretching east to Salina Cruz.

Mexican state-run oil company Pemex's largest

domestic refinery is in Salina Cruz.

To the west, resort town Acapulco should be spared, the NHC

forecast showed. Acapulco was battered by Hurricane Otis last

year and recovery efforts are still ongoing.