Inter company debt

I have two companies, Company A and Company B (both limited companies with the same directors)

Company A has a lot of debt and I need to liquidate the company in the next few months as the company will soon be insolvent

Company B owes company A money and I did not want company B to be liable to Creditors of company A when company A is liquidated.

Can I write off company B's debt to company A before I liquidate company A?

A fast response would be much appreciated

All the best