Jennifer MacIntyre, Canada's climate change ambassador, is stepping down after the sudden death of her husband.

"It is with mixed emotions that I must step down as Canada's Ambassador for Climate Change," MacIntyre tweeted on Tuesday afternoon. "The opportunity to advance Canada's international #ClimateChange #CleanGrowth agenda was an immense privilege. I am confident Canada's important #climate leadership will continue."

Her husband, Michael Fink, passed away in October. He was 48 years old.

The couple met when they were each in St. Petersburg, Russia.

According to an obituary, he had worked for the National Nuclear Security Administration — contributing to American efforts to "secure weapons-grade nuclear material around the world" — and was dedicated to the cause of nuclear non-proliferation.

"Michael spent the final years of his career with Switzerland's Arktis Radiation Detectors, and his daughters are always proud to say 'Daddy works to stop bombs,'" the obituary said.

MacIntyre was appointed in June, filling a position that had been vacant since January 2015. She was previously Canada's ambassador to Switzerland and Liechtenstein.

In her own tweet, Environment Minister Catherine McKenna thanked MacIntyre for her leadership and dedication to the issue of climate change.

"I want to thank Jennifer for her amazing service," McKenna added in a statement from China, where she is travelling.

"She was a very effective climate ambassador and a strong support for our government's efforts to promote climate action and clean growth in the global arena. Climate diplomacy is extremely important and we will be seeking a replacement for this position in due course.

"We are very sorry to see Jennifer leave for personal reasons, but we wish her all the best and deeply appreciate her contribution as Canada's first female ambassador for climate change.‎"