US President Donald Trump watched Saturday's third round of the US Women's Open tournament from a glass-enclosed viewing area at the 15th hole of his Trump National golf resort.

Trump, wearing a white shirt and no tie with a red "Make America Great Again" hat, exchanged greetings with many of the thousands of spectators as he looked out over the green at the par-5 hole on a sunny day in Bedminster, New Jersey, southwest of New York.

The tournament, the richest event in women's golf, is the third major championship of the LPGA season with later majors in the year in Britain and France.

Activists angered by Trump's controversial comments about women during his presidential campaign had urged the US Golf Association to move the tournament, which had been awarded to the Trump property years before his presidential bid.

Among the guests of Trump in his secured viewing area was LPGA veteran Suzann Pettersen of Norway, whom Trump kissed on both cheeks when they greeted each other.

The two-time major champion Pettersen, who accepted a blue cap from Trump, fired a two-over par 74 earlier Saturday.

Trump, who arrived at about the same time the leaders teed off on the opening hole, waved to spectators and thanked some who cheered him. He also applauded players for good shotmaking, though he often watched television coverage from inside the area.

American Lexi Thompson, whose shared 27th after a third-round 74 Saturday, was among those who joined Trump in his special viewing area after her round. She said she didn't feel any extra pressure with a sitting US President at the event for the first time.

"I don't feel extra pressure at all," she said. "This is his golf course. It's cool to have the President of the United States."

Trump's presence also attracted dozens of protesters who were kept outside the club's gates with one holding up a sign that read, "America Lost Putin Won".

Source: AFP