World leaders say they believe an Iranian missile shot down a plane near Tehran, killing 176 people.
The Ukrainian plane crashed shortly after takeoff on Wednesday.
The UK, America, and Canada say it may have been shot down by accident, but Iran has described the claims as "illogical rumours."
Iran's state media says the country is inviting Boeing to join the investigation into the crash.
Their missile strikes on a US airbase in Iraq were prompted by America's assassination of a top Iranian general, Qasem Soleimani.
Donald Trump's been defending the killing during his first campaign rally since it happened: