Donald Trump was tricked into an angry public outburst by a seven-month-old video of an Iranian missile launch, US officials have revealed.

The President responded to claims over the weekend on Iranian state television that the Persian country had tested a medium-range ballistic missile, saying that a purported video of that test  proved the country was a danger to Middle Eastern ally Israel.

But, as it turns out, the videos were actually seven months old, US officials told Fox News. Iran has not launched a missile recently.

“Iran just test-fired a Ballistic Missile capable of reaching Israel,” Mr Trump wrote in a tweet after the video was aired on television. “They are also working with North Korea. Not much of an agreement we have!”

The tweet, and the faked video, came just after the President said that the Iran nuclear agreement reached by his predecessor was an “embarrassment” to the United States, and insulted the Iranian regime in front of the entire world at the United Nations General Assembly.

“We cannot let a murderous regime continue these destabilising activities while building dangerous missiles, and we cannot abide by an agreement if it provides cover for the eventual construction of a nuclear programme,” he said then.

The Iranian government has insisted that any missile programmes they have are only for defensive means, not to launch an offensive on another country like Israel.

“We never threaten anyone, but we do not tolerate threats from anyone,” Iranian President Hassan Rouhani said, also at the United Nations and a day after Mr Trump’s speech.

Mr Trump hasn’t announced publicly whether he plans on keeping the Iranian nuclear agreement, which must be renewed and certified by the US periodically to ensure that Iran is following the basic tenets of the accord.

A war with Iran in the Middle East could prove catastrophic for regional allies to the United States. Experts believe that the Iranian military has the largest arsenal of ballistic missiles in the region, which includes more than 1,000 short- and medium-range ballistic missiles. The country has conducted more than 20 missile tests since 2015 alone.