The President of the Senate (Vice President of the United States) is given that authority in the US Constitution. He may choose not to vote which would have the same effect as voting nay.
As the President of the Senate, he votes to break any tie vote.
executive
The Vice President of the United States is the President of the Senate.. He can not vote unless there is a tie but he can vote to break a tie. Such is his only power.
The President of the Senate (VP of US) votes to break ties.
The vice president.
When there is tie in the Senate (as demonstrated recently when Vice President Pence broke the tie on the repeal of Obamacare following Senator McCain's NO vote)
He is not a member of the Senate but presides over the Senate. According to parliamentary rules, the presiding officer does not vote unless there is a tie vote.
The Vice President of the United States is the President of the Senate.. He can not vote unless there is a tie but he can vote to break a tie. Such is his only power.
To vote to break a tie in the senate
The Vice-President of the United States is the President of the Senate. When he is present, he presides over the Senate (similar to running a meeting) but he does not participate in Senate debates. He votes only if it is necessary to break a deadlock in a Senate vote.
to break a tie in the senate
The Vice-President, who is President of the Senate, can vote to break a tie vote.