Crown Princess Kiko, who celebrated her 53rd birthday Wednesday, has said she does not wish to comment on the postponement of her eldest daughter's marriage to Kei Komuro.

"I believe she (Princess Mako) is thinking through a lot of things. Under such circumstances, I would like to refrain from speaking on current or future matters, including speculating on my daughter's feelings," the crown princess said in a statement.

Princess Mako and Komuro announced their engagement plans in September 2017 and said their wedding would take place last November, but the Imperial Household Agency announced in February last year that the couple would be delaying the event until 2020, citing a "lack of time to prepare."