The UN meteorological agency WMO has said there is only a small chance of an El Nino or La Nina system developing in the Pacific Ocean in the coming months.

The systems can cause extreme weather around the world.

They cause an abnormal warming or cooling of the surface of parts of the Pacific Ocean and lead to heavy rainfall and flooding in some parts of the globe or drought in others.

The World Meteorological Organisation said "neutral conditions" were persisting in tropical areas of the Pacific and were likely to continue through the Northern Hemisphere's summer and autumn.

However, it said "a slight chance of La Nina or El Nino development remains".