| Mr Sanchez, believed to be the ELN's last hostage, appeared in a video on Colombia's RCN TV channel on Wednesday |
Colombia's second-biggest rebel
group has begun the process of releasing a hostage, a key condition for
the start of peace talks with the government, officials say.
But President Juan Manuel Santos said Mr Sanchez had to be released first. The government remained committed to "advancing with this process", he added.