Meghan Markle flies commercial to the US to watch Serena Williams in US Open

Meghan Markle has reportedly taken a commercial flight to the United States.

The reason for the Duchess of Sussex’s trip is to watch her friend Serena Williams play in the final of the US Open.

Markle, 38, flew without Prince Harry or baby Archie, but was accompanied by security staff, according to reports.

READ MORE: Serena Williams appears to support Meghan Markle at the Oscars

Valentine Low, a journalist at The Times, announced the visit on Twitter at 7:43am this morning.

"It is a last-minute trip,” a source told the publication. “Excited to support her friend, and then come back.”

Williams will compete in the US Open finals match tomorrow at 9pm UK time.

The tennis player qualified for the tournament last night, after beating Elina Svitolina in the semi-finals in a match which finished at 1am UK time.

It is believed Duchess Meghan stayed up late to watch the match, according to the Times report. Her flight took place less than seven hours after the match ended.

The Duchess is a close friend to Williams, whom she met during a charity football tournament in February 2014.

READ MORE: Serena Williams says she’s been ‘relying on Meghan Markle at lot lately’

The tennis player attended the Duke and Duchess of Sussex’s royal wedding in May 2018, and more recently Markle was spotted cheering on her friend at Wimbledon.

Markle’s choice of a commercial flight comes in the wake of the recent private jet furore surrounding the Sussexes.

Still, the fleeting nature of the trip has invited some criticism on Twitter, with one user calling the flight “frivolous”. Air travel is a key contributor to your carbon footprint, according to environment experts.

The Duke of Sussex has previously said he and Meghan will have a maximum of two children in a bid to protect the planet.

Buckingham Palace did not immediately respond to Yahoo UK’s request for comment.