That's according to Sky News, Ukrinform reports.
"Instead of just freezing that money, let's take that money, spend it on rebuilding Ukraine and that is, if you like, a downpayment on reparations that Russia will one day have to pay for the illegal invasion that they've undertaken. I've looked at all the arguments and so far, I haven't seen anything that convinces me this is a bad idea," Cameron said.
He also urged politicians in the United States to approve a fresh package of military aid for Ukraine after Republicans blocked the deal.
"If the U.S. votes through the Ukraine support package, it will give enormous fillip to European countries," he said, following calls from President Joe Biden encouraging Congress to approve the aid.
Cameron said in his speech in the House of Lords (the upper house of parliament) that there would be no reduction in military support for Ukraine in 2024.