The White House said the intention was to “establish a line of communication” with the Russian government. One official called it an "inconsequential hello" and said Mr Kushner had not met Mr Kislyak since.

On Thursday Attorney General Jeff Sessions recused himself from any future investigation examining communications between Trump officials and Moscow.

He did so after it was revealed he had himself spoken twice to Mr Kislyak and not revealed it during the confirmation hearing for his new post.

Mr Sessions was accused of "lying under oath" by Democrats in Congress who called on him to resign.

Several other Trump campaign advisers - national security advisers JD Gordon and Walifd Phares, and former foreign policy adviser Carter Page - also spoke with Mr Kislyak at the Republican National Convention in Cleveland last July, it emerged.