The Magpies defender admits he did not mean to come across as arguing with his own supporters, but merely wanted to show that he cared.
The 26-year-old addressed the visiting fans after the 1-0 loss on Wednesday night, and appeared to become embroiled in an angry exchange with members of the incensed support.
The Dutch full-back said that he was upset after the late defeat, but admits that he allowed things to get out of hand by letting his emotions get the better of him.
Janmaat told the Mirror: "I was very emotional after the game. We had lost. I understand the fans are not happy, but neither are the players. It was not my intention to “confront” them. I did not want to get in a confrontation.
"It was more like I wanted to show I care, and say: '“Look I care. Look, we need you now. We need you because it is a really important period, the next couple of months'. That was the idea in my head. It was an emotional reaction. I do not normally do that.
“I have a good relationship with fans. I wanted to hear what they were feeling. We all felt like s**t losing like that in the 80th minute. We understand they are angry. We have got to win. This is the only result that counts."
The Magpies seventh consecutive away defeat saw them slip to second-bottom in the Premier League table, but their survival is still in their own hands.
Newcastle are in the relegation zone only on goal difference with a game in hand over most of their fellow strugglers, and victory against Bournemouth on Saturday would lift them three points clear of the bottom three.