US President Donald Trump’s son has said his 2016 meeting with a Russian lawyer was about “essentially nothing” relevant to claims of collusion.

Donald Trump Jr called the media uproar over the meeting “the ultimate distraction” from his father’s success.

Mr Trump Jr’s meeting with a Kremlin-linked attorney at Trump Tower in New York could constitute a breach of US campaign rules, experts say.

The president argued the Trump Tower meeting was legal in a tweet on Sunday.

Mr Trump said his son took the meeting to “get information on an opponent”, contradicting a previous statement from the Trump camp.