The US Senate has approved a bill to construct a 700 mile fence along the Mexican border in an attempt to stop illegal immigration.

The proposed fence will stretch along the border states of Texas, New Mexico, Arizona and California, and is set to cost $1.2billion.

This follows earlier attempts to combine border security with a guest-worker programme for the 12 million immigrants currently living illegally in the United States.

Mexico's President, Vicente Fox, has compared the fence to the Berlin Wall.