Promotion and relegation will be a key element of a revamped PGA Tour from 2028.

New details were announced at a news conference fronted by former world number one golfer Tiger Woods, before this week's Travelers Championship in Connecticut.

Woods is the chairman of the tour's Future Competitions Committee, which has formally approved changes which will lead to two separate tiers of competition on the PGA Tour.

"Over the past eight months, the Future Competition Committee has spent a lot of time on a very important and fundamental question: How do we build the strongest possible version of the PGA Tour?" Woods said.

"This work was never about any one player or person. It was about bringing together different perspectives, having honest, hard conversations and thinking boldly about what is best for the game that we all love."

It was the 15-times major champion's first public appearance since taking a period of recovery following a car crash in Florida last March. Woods has pleaded not guilty to a charge of driving under the influence.

The proposed schedule changes will mean that the world's leading golfers will play on the the PGA Tour's "Championship Series" in tournaments comprising 120-man fields.

It will create a season of 23 or 24 tournaments that will include the four majors and will run from January to August.

This elite strata will compete for at least $20m (£15.2m) at each event and the top 90 at the end of the year will preserve their status.

Beneath this level, a "Challenger Series" will run concurrently with purses worth at least $4m. Any playerwho wins two of these events in the same season will gain immediate promotion.

Full details have still to be agreed and among the outstanding issues is the American circuit's relationship with the European based DP World Tour.

Their "strategic alliance" is up for renewal next year but PGA Tour chief executive Brian Rolapp indicated that, by 2028, the European tour is likely to have a role in helping stage international tournaments, including national opens, in the autumn months.

Currently, the top 10 finishers on the DP World Tour's Race to Dubai, who are not already playing in the US, gain PGA Tour cards for the following season. It is not certain whether this will continue.

"It hasn't been decided," Rolapp said. "We've had a really successful relationship with the DP World Tour, inclusive of those cards."

The tour boss, who will succeed Jay Monahan as PGA Tour commissioner next year, added: "That's one of the many things we're speaking about."

Rolapp is promising to take the PGA Tour to new venues in the United States and said that 10 of 15 courses needed for the 2028 Championship Series, which will all have halfway cuts, have been identified.

Using a uniform points system, the series will crown an individual champion before the usual end-of-season Tour Championship.

That tournament will become matchplay and move to different locations rather than staying at its traditional home at East Lake in Atlanta.

Although exact details have still to be established, 20 golfers on the lower Challenger Series will earn promotion to the higher tier at the end of a season.

There will also be four to six "last chance" competitions in the autumn for those facing relegation to still preserve Championship status.

And Championship players will not be allowed to compete in Challenger events in the same season.

"We think for the integrity of what we're delivering to our tournament partners that it was important to do that," Rolapp said.

It does mean those lower events will be potentially bereft of star names and, at last week's US Open, Rory McIlroy expressed concern that this track would be "a glorified Korn Ferry Tour" which is currently a low-profile feeder circuit to the PGA Tour.

But the Masters champion welcomed Tuesday's announcement, saying in a statement that it is "a positive step for professional golf".

He added: "As more details emerge, it is encouraging to see the PGA Tour reaffirming the importance of meritocracy and creating a structure that will serve both players and fans well."

McIlroy also welcomed adding overseas events after the main season has been completed, in collaboration with the DP World Tour.

"The commitment to elevate some of these historic international tournaments and national opens is incredibly important for the game," the Northern Irishman said.

Last week, McIlroy had said that the way the PGA Tour was prior to the 2022 arrival of the breakaway LIV tour "was actually pretty good".

But Rolapp says the 2028 changes are vital to the tour's future.

"If you're competing for media dollars, which is the economic lifeblood of every sport in this country, you need to be constantly improving the product," he said.

"I think we looked around and we saw what we need to do to increase fans' attention and create more value for our partners and felt this was necessary."