Bernie Sanders has undergone heart surgery on the presidential campaign trail, forcing him to cancel events and appearances “until further notice”.

On Wednesday the Vermont senator’s campaign team reported that he was “conversing and in good spirits” as he recovered from the procedure, which took place in Las Vegas.

During an event on Tuesday, the 78-year-old experienced “chest discomfort”, and a blockage was discovered in an artery, the campaign said.

A spokesman said: “Two stents were successfully inserted… He will be resting up over the next few days. We are cancelling his events and appearances until further notice, and we will continue to provide appropriate updates.”

Thinking of @BernieSanders today and wishing him a speedy recovery. If there's one thing I know about him, he's a fighter and I look forward to seeing him on the campaign trail soon.

— Kamala Harris (@KamalaHarris) October 2, 2019

Bruce, Team Warren, and I are sending all our best wishes for a speedy recovery to @BernieSanders. I hope to see my friend back on the campaign trail very soon.

— Elizabeth Warren (@ewarren) October 2, 2019

Mr Sanders, who currently trails Elizabeth Warren and Joe Biden in the polls for the Democratic party nomination for the presidency, was due to attend a gun policy forum in Nevada on Wednesday.

He was then scheduled for several appearances in California over the following days.

Mrs Warren tweeted: “Bruce, Team Warren, and I are sending all our best wishes for a speedy recovery to @BernieSanders. I hope to see my friend back on the campaign trail very soon.”

Other campaign rivals, including Kamala Harris and Cory Booker, also sent well wishes.