The Archbishop of Canterbury Most Reverend Justin Welby, the Church of England's most senior ranking cleric, admitted that there's one thing he's quite nervous about when he officiates Prince Harry's wedding to Meghan Markle on May 19, especially since it had happened once before.

(Reuters/Stefan Wermuth) Archbishop Justin Welby will officiate the wedding of Prince Harry and Meghan Markle on May 19.

In an interview for ITV News, Welby said he worries he might drop the ring, while the groom's grandmother and the Supreme Governor of the Church of England, Queen Elizabeth, is at the wedding. He also hopes he won't forget the order of the vows.

Welby amusingly confessed he forgot the order of the vows at his own child's wedding a few years back. Then, last September, he caused a slight commotion when he did drop the ring at the wedding of a journalist. He was placing the ring on the couple's hands when one rolled down to the front pew without the archbishop noticing.

Meanwhile, as the archbishop prepares for the royal wedding, he's also helping out the couple through the process properly, especially since Markle is a divorcee. Early this month, Welby baptized Markle in a private ceremony attended only by a handful of relatives on both sides.

The actress' confirmation followed the baptism. After which, the couple and their guests had dinner at the house of the Prince of Wales, Charles, and the Duchess of Cornwall, Camilla.

"It was beautiful and sincere and very moving," the archbishop said of the ceremonies. "It was a great privilege," he continued.

Markle isn't required to convert to the Church of England to marry Prince Harry. The actress, who grew up with Protestant parents and went to school at a Catholic girls-only institution, wanted the baptism out of respect for the Queen.

Prince Harry and Markle, who announced their engagement in November 2017 after almost 18 months of dating, will be married at the St. George's Chapel in Windsor Castle.