A Canadian woman has been jailed for 22 years in the US for sending letters laced with ricin poison, including to Donald Trump when he was president.

Pascale Ferrier, 56, agreed to the sentence in January after pleading guilty to biological weapons charges.

The deadly envelope addressed to Mr Trump was intercepted in September 2020 before delivery to the White House.

Ferrier told the court that she regretted that her plan had failed and that she "couldn't stop Trump".

In a long-winded address to the court, she also said that she saw herself as an activist not a terrorist.

"I want to find peaceful means to achieve my goals," Ferrier added.

The FBI found her fingerprints on the letter to Mr Trump, which urged him to drop out of the presidential race.

"I found a new name for you: 'The Ugly Tyrant Clown'," she wrote in the letter, according to FBI charging documents.

District Judge Dabney Friedrich sentenced Ferrier to 262 months - just shy of 22 years - in prison. She will be deported from the US after serving her sentence and faces supervision for life if she ever returns.

Judge Friedrich told Ferrier her actions were "potentially deadly" and "harmful to you, harmful to society, harmful to the potential victims".

Ferrier also admitted sending similarly tainted letters to eight Texas law enforcement officials.

In 2019, she was detained in the state for about 10 weeks for unlawfully carrying a weapon and driving without a valid licence, and she blamed those officials for that detention, according to a US justice department statement.

Ferrier, a dual citizen of France and Canada, was arrested crossing the border into Buffalo, New York in September 2020. She was carrying a gun, knife and rounds of ammunition.

She later admitted to making the ricin - a poison made from the waste material left over from castor beans processing - at her Quebec home, and placing it into an envelope with the letter.

There is no known antidote to ricin. Depending on the dose, it can cause death within 36 to 72 hours, according to the US Centers for Disease Control and Prevention.

In 2014, a Mississippi man was sentenced to 25 years in prison after sending ricin laced letters to President Barack Obama and other officials.