A total solar eclipse crossing North America is darkening skies along a path through Mexico, the United States and Canada.

The moon started to cover up the sun as a partial eclipse began over the South Pacific during the afternoon.

Millions along a narrow corridor in North America from Mexico’s Pacific coast to eastern Canada were hoping for clouds to clear as they eagerly wait for totality to reach their location.

Totality will last up to four minutes and 28 seconds in certain spots.

Cheers broke out along the beach in the resort city of Mazatlan in Mexico as the moon began to pass over the sun.

Hundreds in a beachside park had passed the time readying their equipment and listening to a youth orchestra play Star Wars songs while a large screen projected images of Princess Leia behind them.

Luz Elena Aguillon de la O sat in the grass with a group of 14 family and friends who had gathered from Mexico City, Guanajuato and Mazatlan to take in the spectacle.

“Happy to be here with family, friends sharing a singular, unrepeatable event that the universe and nature give us,” she said.

The weather is not looking good for a large part of the eclipse’s path. Clouds could get in the way for a stretch of the route, with the heaviest clouds expected in parts of Texas.

There are patches that may be clear. And meteorologists point out that the eclipse might still be visible if the clouds are high and thin.

The one area where clear skies are expected is northern New England through to Canada.

That area has “a pretty solid lock to be able to see the eclipse pretty crystal clear”, said National Weather Service meteorologist Cody Snell.

Fifteen US states get a chance to see the full eclipse, although just a small part of Tennessee and Michigan are included. The length of totality varies by location.

The moon’s shadow that falls on Earth follows along a path that is 115 miles wide.

Practically everyone in North America will have a chance at catching at least a partial eclipse. The farther from the path of totality, the smaller the moon’s bite will be out of the sun.

An eclipse is worth marveling at.

But don’t be silly, folks – play it safe and wear protective eyewear. pic.twitter.com/S6REAiZ735

— President Biden (@POTUS) April 8, 2024

President Joe Biden posted a brief video on X, formerly Twitter, to encourage Americans to wear eye protection when viewing the eclipse – in a subtle dig at his predecessor and 2024 rival, former president Donald Trump.

“Folks, enjoy the eclipse, but play it safe, don’t be silly,” Mr Biden said in a video showing him donning eclipse glasses and looking skyward from the balcony outside the Blue Room of the White House.

That is the spot where Mr Trump glanced up toward the sun without eye protection in 2017.

Mr Biden is travelling to Wisconsin, which, like Washington, will experience a partial eclipse on Monday.