(Adds quote clarifying Ashton **t seeking extension to talks) LUXEMBOURG, Oct 20 (Reuters) - European Union foreign policy chief Catherine Ashton said on Monday she will continue leading nuclear negotiations with Iran until a deal is reached but is determined to meet a **vember deadline for an accord. Her five-year term as EU foreign policy chief ends on Oct, 31, and she had said she would stay on as nuclear negotiator until **v. 24, the deadline for reaching a long-term settlement with Iran over its nuclear programme. ...