McCain, a longtime lawmaker from Arizona and Navy veteran who endured brutal torture as a prisoner of war in Vietnam, died Saturday at age 81 after a struggle with brain cancer. The senator's outsized presence came not only from his military and political record but also from his frank talk and recent willingness to call out President Donald Trump for perceived violations of American norms when few others in his Republican Party would.

The letter closes: "Americans never quit. We never surrender. We never hide from history. We make history. Farewell fellow Americans, God bless you, and God bless America."

"Do not despair of our present difficulties but believe always in the promise and greatness of America, because nothing is inevitable here," the Republican senator and former GOP presidential nominee wrote in a letter read by advisor Rick Davis on Monday.

Sen. John McCain , in a final message to the United States written before his death, said that he "lived and died a proud American" and expressed hope that the country would emerge from its current trials "stronger than before."

After briefing reporters on memorial services that will take place this week throughout the country, a tearful Davis read the senator's final message to the country. In it, McCain said he hoped that his "love for America will be weighed favorably" against the "mistakes" he made in his life.

The senator — who returned to Washington last year after his cancer diagnosis to warn about the effect tribalism and hostility could have on the chamber's ability to govern — emphasized decency and civility in his letter. The occasional critic of Trump also appeared to lament the president's effect on civil discourse in the country.

"We weaken our greatness when we confuse our patriotism with tribal rivalries that have sown resentment and hatred and violence in all the corners of the globe. We weaken it when we hide behind walls, rather than tear them down, when we doubt the power of our ideals, rather than trust them to be the great force for change they have always been," McCain wrote, in what seems to be a reference to the president's nationalist rhetoric about making America "great" again, and his effort to construct a wall on the U.S.-Mexico border.

The senator said he still had a "heartfelt faith" in Americans that he felt in 2008, when he conceded the presidential election to former President Barack Obama.

Read McCain's farewell message in full: