Ivanka Trump congratulates Boris Johnson on becoming leader of ‘United Kingston’

Ivanka Trump has been mocked after congratulating Boris Johnson on becoming the next prime minister of the "United Kingston".

The tweet from the US president's daughter and close adviser was up for around half an hour before being deleted, giving Twitter users plenty of time to poke fun at the mistake.

The tweet closely follows an error by her father Donald Trump in which he described meeting the "Prince of Whales".

One Twitter user posted: "No Whales, isn't in England. It's part of the United Kingston."

Shortly after Ms Trump's error, the phrase "United Kingston" was trending on Twitter in the UK.

It is not the first time a member of the Trump family has made a gaffe on Twitter.

In 2017, President Trump tweeted just after midnight in Washington: "Despite the constant negative press covfefe."

He later attributed the mistake to the late hour and tweeted: "Who can figure out the true meaning of covfefe? Enjoy!"

Later in the year, the White House released a press statement that said one of the goals of an Israel trip was to "promote the possibility of lasting peach".

Mr Johnson was elected leader of the Conservative Party in a contest that saw him win 92,153 votes – beating Jeremy Hunt's 46,656.

He will take over the role of prime minister after Theresa May informs the Queen of her resignation on Wednesday.