The United States is offering additional logistical help to Mexico to combat forest fires which are threatening to cause a huge ecological disaster.

Already large areas of thick jungle known as the Chimalapas jungle in the south of the country, which is home to many endangered species, have gone up in flames.

Progress in tackling the fires has been slow, and a thick haze and high winds have grounded water-carrying planes for several days.

The BBC Mexico correspondent says the Americans are also worried about the effect of the fires on public health on their side of the border.

Last month, smoke blew across the border into Texas, forcing many people to stay indoors.