The tennis firebrand was asked what he thought about being fined a record $US113,000 ($A167,000) for his spectacular meltdown in Cincinnati this month.

"The ATP is pretty corrupt anyway. I'm not fussed about it at all," he said in a development that will almost certainly force the governing body of men's tennis to suspend the Australian, having already said it was considering such a move.

"I was fined $113,000 K for what? Why are we talking about something that happened three weeks ago when I just chopped up someone first round of a US Open?"

US Open officials had given Kyrgios the green light to play the final grand slam of the year despite tennis chiefs continuing to weigh up whether or not the temperamental talent should be suspended for his latest outburst in Cincinnati.

The ATP offered no time line around when it would make any decision on Kyrgios' fate when quizzed on the eve of the Open, which started on Monday.

Believed to be the biggest fine in the sport's history, Kyrgios was slapped with separate penalties for an audible obscenity, ball abuse, verbal abuse towards the umpire, leaving the court and four counts of unsportsmanlike conduct during his explosive second-round loss to Karen Khachanov.

In addition to the fines, the ATP said it was "looking further into what happened during and immediately after the match to see if additional action is warranted under the Player Major Offence section of the code and that could result in an additional fine and/or suspension".

But the 24-year-old was unrepentant after progressing to the second round at Flushing Meadows.

"Have you ever sworn at someone before?" he countered at a journalist.

"... You're not an elite athlete."

Asked if he was saying it was acceptable for elite athletes to swear, he said: "No, I'm just saying people get frustrated. It happens."

Meanwhile, Jordan Thompson, Alexei Popyrin, Thanasi Kokkinakis and Ajla Tomljanovic also won on Tuesday.

Thompson was superb in clubbing Joao Sousa 6-3 6-2 6-4, Popyrin beat Federico Delbonis 6-1 7-5 7-6 (7-5), Kokkinakis's 6-3 7-6 (10-8) 6-7 (4-7) 6-2 victory over Ilya Ivashka was his first at a slam since 2015 and Tomljanovic pulled off a remarkable 1-6 7-5 6-1 comeback win over Marie Bouzkova from a set and 5-2 down against the Czech.

But 2018 Open quarter-finalist John Millman was no match for Rafael Nadal, falling 6-3 6-2 6-2 to the 18-times major winner, while Astra Sharma lost 6-3 6-4 to Magda Linette.

Men's singles, first round

Women's singles, first round

Australian Associated Press