He was speaking after an attempt to scrap his position was abandoned on the first day of the party’s annual conference in Brighton.
Jeremy Corbyn, whom Mr Watson has clashed with in the past on Brexit and Labour’s handling of antisemitism claims, moved to try and quell a growing row that threatens to overshadow the gathering.
His intervention means that the role will instead be the subject of a review.
The attempt was led by Jon Lansman, head of the Corbyn-supporting Momentum group.
Addressing the row as he arrived in Brighton, Mr Watson said: “We’ve had a bad start to our conference, I can’t do anything about that.”
Asked if he thought the Labour leader knew about the plot, Mr Watson said: “I don’t know what Jeremy knew or didn’t know.”
As for what his message to the Labour leader would be, he responded: “Both of us would want to reunite the conference after what has been, frankly, quite a ridiculous start to it and totally unnecessary.”
Mr Watson also had strong words for Mr Lansman, saying: “I think it says there are some people who don’t think clear-headedly, who risk us having a transformative government by playing sectarian games,” he said.
“I put Jon Lansman in that category and I think it’s very sad because I think he has undermined himself and the members of his organisation, many of whom have been in touch with me today and said they were not consulted when he did that and they were very disappointed with him personally.
“But that’s politics, I’ve been around a long time and I want us to reunite now.”
Union leader Len McCluskey, who once called Mr Watson a “f****** disgrace over his criticism of the party’s general secretary, sought to put him on notice despite the reprieve.
“We need unity between our leaders. I hope Tom Watson is listening,” the Unite general secretary told a Morning Star fringe event.
“The truth of the matter is a deputy leader – their prime reason and role is to support the leader.”
The move against Mr Watson was launched at a meeting of Labour’s National Executive Committee on Friday – an event he was not at because of family commitments.
Although it was ruled out of order by chair Wendy Nichols, those at the meeting voted 17-10 to debate it anyway. This was just short of the two-thirds majority required under party rules.
However, the motion was set to be considered at Saturday morning’s meeting, a matter of hours before the start of the conference.
This was when Mr Corbyn intervened with his call for a review of the position, rather than abolition. The bid to scrap the role was not put to a vote.
The attempt to oust Mr Watson drew condemnation from many figures within the party, including former prime minister Tony Blair and former leader Ed Miliband.
Quizzed about the row as he arrived in Brighton, Mr Corbyn refused to say when he first knew about the attempt to oust Mr Watson.
He also would not say if he had full confidence in his deputy, saying: “Tom Watson is the deputy leader of the party and I enjoy working with him.”
He told reporters: “The NEC agreed this morning that we are going to consult on the future of diversifying the deputy leadership position to reflect the diversity of our society.”
The Labour leader said there was a “happy and united mood” at the NEC meeting – and added the party’s conference will be “totally united on defeating this Tory government”.