However, he had decided to defer making a decision until next Tuesday, the day before the medals were due to be auctioned.
"I just want to reflect on the situation ... I will be giving it my full consideration," Mr Munro said.
Before arriving at a decision, there were other factors to consider, he said. Mr Munro did not wish to elaborate.
London auction house Dix Noonan Webb said the medals could fetch $81,000 to $102,000.
Lord Ashcroft told Radio New Zealand that his proposal was a win-win situation, whereby Mr Munro secured substantial funds for the upkeep of the memorial and his medals and associated memorabilia were gifted to the museum for the benefit of the nation.
The philanthropist visited the museum on Monday and viewed one of the last remaining Avro Lancaster Bombers housed in its aviation display hall.
Lord Ashcroft and the museum said that whatever the outcome they would respect and support Mr Munro's decision, but would not be bidding if the proposal was rejected. The medals include the Distinguished Service Order and the Distinguished Flying Cross.
Meanwhile, Mr Munro will not attend the London unveiling of his portrait next month by world-renowned artist Richard Stone.
"I was invited to go, but my age is catching up with me," the 95-year-old said.
Mr Munro would dearly love to be there but said attending would be unwise for health reasons.
Stone, whose canvases of British royalty have included notable figures such as the Queen Elizabeth II and the late Queen Mother, was in Tauranga last May doing sketches of Mr Munro.
The artist had planned to unveil the portrait by the end of 2014 but was then called on to deliver a fresh portrait of the Queen and also travelled to Canada to do the portrait of another Dambusters veteran.
Lord Ashcroft
* Tory peer, international businessman, philanthropist and author
* Founder and chairman of Crimestoppers
* His collection of 180 Victoria Crosses was put on public display in 2010 in a purpose-built gallery at the Imperial War Museum
* A trustee of the Imperial War Museum, he has written five books on gallantry