LONDON, Sept 29 (Reuters) - British Prime Minister Liz Truss and finance minister Kwasi Kwarteng will meet the head of the country's independent fiscal watchdog on Friday, after days of financial market chaos triggered by the government's planned tax cuts.

Truss and Kwarteng will meet Richard Hughes, chair of the Office for Budget Responsibility (OBR), to discuss the budget forecast process and economic and fiscal developments since March, the UK's Treasury said on Thursday.

Kwarteng unveiled a string of tax cuts last week in a fiscal statement that was not accompanied by OBR forecasts and which sent British financial markets into turmoil.

The finance minister has asked the OBR to produce a first draft of its next economic forecasts on Oct. 7.

He plans to announce a budget statement on Nov. 23 that will include new forecasts and detail the cost of the borrowing and measures to cut debt.

A committee of lawmakers in Britain's parliament has urged Kwarteng to bring forward his budget statement.

Truss and Kwarteng defended their economic plans earlier on Thursday, with the prime minister saying urgent action was necessary to help economic growth. (Reporting by Sachin Ravikumar; editing by William James and Sam Holmes)