Former president George HW Bush has greeted mourners filing through a Houston church as they paid final respects to his wife of 73 years, former first lady Barbara Bush.

A spray of dozens of pink and yellow roses covered her coffin in the sanctuary of St Martin’s Episcopal Church.

The 93-year-old former president sat in a wheelchair just a few feet from the coffin, smiling as people shook his outstretched hand and offered condolences.

Mrs Bush died on Tuesday aged 92 at the couple’s Houston home, where her husband was by her side. Many women attending the day-long viewing wore blue, Mrs Bush’s favorite colour.

The nation’s 41st president had not been scheduled to attend but decided to go after watching video from the church, where about 1,600 people had passed through in the first hour. He stayed for about 15 minutes.

Barbara Bush
Mourners pay tribute to Barbara Bush in Texas (Evan Vucci/AP)

“I think he was very touched by all of the people who were taking the time out of their lives,” family spokesman Jim McGrath said.

Visitors went through security checks before boarding shuttle buses to travel a few miles to the nation’s largest Episcopal church.

Lucy Orlando was among more than 100 people in the queue well before the bus service began, after travelling from Florida. Originally from Haiti, the 74-year-old said she had admired mrs Bush for years, including for her work promoting literacy .

“She was a very sweet lady and she loves people,” said Mrs Orlando, who was carrying a grey suitcase containing framed photos of the couple and members of their family, including former Florida governor Jeb Bush and former president George W Bush and his wife, Laura.

Varney Johnson, a 49-year-old local social worker originally from Liberia, said he also came to honour the former first lady’s work in supporting literacy efforts, saying: “This woman dedicated her life to educating children.”

Barbara Bush
Mourners have been remembering former first lady Barbara Bush (David Phillip/AP)

Jessica Queener, who works in special education and wears a cochlear implant to help with hearing loss, said Mrs Bush’s work in education and helping people with disabilities “really resonates with me on a personal level but also professionally”/

“I believe that Barbara Bush is a mother and a grandmother to every American,” added Jamie Sumicek, 52, of Houston. “Whether you’re Democrat or whether you’re Republican, whether you’re young or old, she is the matriarch of America. That’s what moved me to visit.”

A hearse containing the former first lady’s coffin arrived before daybreak at the church. Her body was to be in repose until midnight.

The invitation-only funeral will be held on Saturday behind her husband’s presidential library at Texas A&M University, about 100 miles north west of Houston. The burial site is in a gated plot surrounded by trees and near a creek where the couple’s three-year-old daughter, Robin, who died of leukemia in 1953, is buried.

In a statement released, the family said Mrs Bush had selected son Jeb to deliver a eulogy along with her longtime friend Susan Baker, wife of former secretary of state James Baker, and historian Jon Meacham, who wrote a 2015 biography of her husband.

Some 1,500 guests were expected to attend, including first lady Melania Trump, former president Bill Clinton and his wife, Hillary, and former president Barack Obama and his wife, Michelle.