US TV journalist Kristen Welker has revealed the struggles with infertility that she and her husband John Hughes have gone through as they await the birth of a daughter through a surrogate.

Welker, NBC News’ chief White House correspondent and the moderator of last autumn’s final presidential debate between Joe Biden and Donald Trump, said on the Today show that their daughter is expected in June.

She shared a copy of a letter she has written to her unborn daughter, saying: “I cannot wait until the moment I hold you for the very first time – it is all I have dreamed about for years.”

The letter described lengthy fertility treatments and the day a doctor told them they would need a surrogate.

“On that day, I cried so many tears that I didn’t think they would ever stop,” she wrote.

“I felt as though I had let you down because I couldn’t carry you myself.”

She wrote that she could not wait to share life’s lessons with her.

“It is OK to ask for help; in fact, it can be empowering,” Welker wrote.

“Families are made in all different ways, come in all different shapes and sizes, and all families should be celebrated.”

NBC said Welker would be doing stories about infertility on the weekend edition of Today.