MIAMI -- Hurricane Cristina has formed off Mexico's Pacific coast.

The hurricane's maximum sustained winds early Wednesday are near 120 kph and the U.S. National Hurricane Center says additional strengthening is expected during the next two days.

Cristina is centred about 425 kilometres south of Manzanillo, Mexico, and is moving west near 9 kph.

The Hurricane Center says swells generated by Cristina are affecting parts of Mexico's south central and southwestern coast. The swells could cause life-threatening surf and rip current conditions.