George HW Bush's passing comes just months after the death in April of his wife Barbara Bush. (AFP)

Former US president George HW Bush, who helped steer America through the end of the Cold War, died at age 94 late on Friday night.

"George HW Bush was a man of the highest character and the best dad a son or daughter could ask for." his son, former president George W Bush, said.

He is survived by his five children and 17 grandchildren.

Tributes started pouring in as the news of his death was announced by his family today.

Former US President Barack Obama says America has lost a patriot and humble servant in George Herbert Walker Bush.

America has lost a patriot and humble servant in George Herbert Walker Bush. While our hearts are heavy today, they are also filled with gratitude. Our thoughts are with the entire Bush family tonight – and all who were inspired by George and Barbara's example. pic.twitter.com/g9OUPu2pjY — Barack Obama (@BarackObama) December 1, 2018

One of his grandsons, George P Bush, says George HW Bush was the "greatest man I ever knew."

My grandfather was the greatest man I ever knew. His life spanned the American Century—he fought in World War II ... took part in the Texas oil boom ... served out a distinguished career in public service including serving as president during the final days of the Cold War. pic.twitter.com/6i68EPVC3j — George P. Bush (@georgepbush) December 1, 2018

Populist FDR Democrat Brandon Presley says Former President Bush served America "with dignity both home and abroad."

Rest In Peace President George H. W. Bush. You served America with dignity both home and abroad. Throughout the world you projected honesty, integrity and a love of freedom. — Brandon Presley (@BrandonPresley) December 1, 2018

"The entire Bush family is deeply grateful for 41's life and love, for the compassion of those who have cared and prayed for Dad, and for the condolences of our friends and fellow citizens," a statement from his family said.

US President Donald Trump released a statement on Twitter saying President Bush inspired generations of his fellow Americans to public service.

Statement from President Donald J. Trump and First Lady Melania Trump on the Passing of Former President George H.W. Bush pic.twitter.com/qxPsp4Ggs7 — Donald J. Trump (@realDonaldTrump) December 1, 2018

White House advisor Kellyanne Conway tweeted: "Heartfelt sympathy and deep condolences to the entire Bush family on the passing of our 41st President, George HW Bush. He devoted his life to his family and his country. Thank you, sir."

Senior Congress leader Shashi Tharoor says George HW Bush was a warm, unassuming and friendly person.

Sorry to hear of the passing of President George HW Bush. He was a warm, unassuming & friendly person who nonetheless suffered the image of an out-of-touch patrician & lost his bid for re-election in 1992. I had the greatest respect for his internationalist instincts. May he RIP. pic.twitter.com/Te98gCGjml — Shashi Tharoor (@ShashiTharoor) December 1, 2018

Former US president Bill Clinton, who defeated Mr Bush in the 1992 election, says he will "always hold our friendship as one of my life's greatest gifts."

Hillary and I mourn the passing of President George H. W. Bush, and give thanks for his great long life of service, love and friendship. I am grateful for every minute I spent with him and will always hold our friendship as one of my life's greatest gifts. https://t.co/1CYdrIeKmz — Bill Clinton (@BillClinton) December 1, 2018

Former president Richard Nixon's daughters, Tricia Nixon Cox and Julie Nixon Eisenhower, say: "George HW Bush lived a life that was purposeful, and extraordinarily rewarding -- for our nation, and for our world."

"President Bush has left us for one last flight but his destination isn't unknown. He's flying into the arms of the love of his life, Barbara," says Hollywood actor and former California governor Arnold Schwarzenegger.

Apple CEO Tim Cook says George HW Bush taught all of us about leadership.