Arizona and Texas are deploying personnel to help fight drug trafficking and illegal immigration

Arizona and Texas have answered Donald Trump's call for troops to help fight drug trafficking and illegal immigration at the US-Mexico border.

The states will send 400 members of the National Guard by next week, with 250 of them arriving over the weekend.

President Trump is hopeful more will follow, having told reporters on Wednesday that he wanted to send up to 4,000 troops.

Previous deployments include Barack Obama sending 1,200 members to the border eight years ago and George W Bush sending 6,000 back in 2006.

In 2014, around 1,000 Guard members were deployed by Texas governor Rick Perry - now Mr Trump's energy secretary - in response to a surge in the number of unaccompanied children crossing into the state from Mexico via the Rio Grande river.

Mr Trump has said he wants to deploy at least 2,000 to combat "the lawlessness that continues at our southern border", suggesting he wants to use the military there until progress is made on his proposed border wall.