Tulsi Gabbard has resigned as Donald Trump's top intelligence chief, citing her husband's recent diagnosis with a rare form of cancer, following months of growing friction over the President's decision to launch a war against Iran.

Gabbard met with Trump in the Oval Office on Friday, where she delivered her resignation letter. She will officially depart as Director of National Intelligence on June 30.

In her formal resignation letter, Gabbard thanks Trump and says she is 'deeply grateful for the trust you placed in me and for the opportunity to lead' the top intelligence agency for the year and a half.

'Unfortunately, I must submit my resignation,' Gabbard writes. 'My husband, Abraham, has recently been diagnosed with an extremely rare form of bone cancer.'

This is a developing story...