Kate Middleton Apologizes to Irish Guards For Missing Colonel's Review

Kate Middleton's sending her regrets to an iconic English military squadron ... apologizing for not attending an annual tradition months after announcing her cancer diagnosis.

The Princess of Wales sent a letter to the Irish Guards earlier this week -- which they posted to X -- applauding them for their vigorous training and preparation for the Colonel's Review ... a last-minute rehearsal for a much larger parade.

Middleton -- who serves as the regiment's colonel ceremoniously, and would usually attend and salute the men before an event called Trooping the Colour -- then apologizes for not being able to come this year. While she doesn't give a reason, it's pretty clear her health's keeping her away.

The Irish Guard -- a foot guard regiment serving as both protectors of the Royal Family and in active combat roles -- will take part in Trooping the Colour ... a large parade held annually honoring the official birthday of the monarch.

It's unclear if KM will appear at the actual event -- again, this was just one rehearsal -- set for next Saturday. Kensington Palace has not yet made a statement regarding the princess' attendance, although it has been reported that she won't be coming.

Princess Kate's stayed out of the public eye since revealing she had cancer in a shocking X post in March ... and, it would come as a surprise to many if she did pop up at Trooping the Colour.

Prince William attended a celebration in Normandy to mark the 80th anniversary of D-Day earlier this week sans Kate. He told a veteran who asked about her she's feeling much better -- but, it seems she's not up to public engagements quite yet.

There's still no timetable for her return to public duties ... and, we'll have to wait for Kensington Palace's next announcement.