George W. Bush broke his silence on President Donald Trump's leadership, after refusing to criticise publicly those who succeeded him since he left the Oval Office eight years ago, media report said on Monday.

"I don't like the racism and I don't like the name-calling and I don't like the people feeling alienated," Bush, 70,  told media in an interview. "Nobody likes that".

The former President, joined by his wife Laura, spoke to the magazine in the painting studio of their Dallas home to launch his first art book, "Portraits of Courage: A Commander in Chief's Tribute to America's Warriors". 

The collection of portraits of the injured warriors of America's war on terror aims to raise awareness and funds for the post-9/11 veterans' health care and employment programmes of the George W. Bush Presidential Centre.

Talking about the Trump's January 20 inauguration, which was attended by both the former President and his wife, Bush said: "First of all, we were thrilled to be there. It's a beautiful ceremony, it really is. It's a peaceful transfer of power, which is very reassuring."

However, Bush called the political climate in Trump's Washington "pretty ugly", but said he was not feeling anxious about the direction of the country. 

"Not really. I'm optimistic about where we'll end up. … We've been through these periods before and we've always had a way to come out of it. I'm more optimistic than some."

Asked if he felt compelled to play a leadership role in these divisive times, Bush said: "No. When President (Brack) Obama got elected, friends would call and say 'You must speak out! You must do this, you must do that'.

Turns out, other people are doing the same thing this time. I didn't feel like speaking out before because I didn't want to complicate the job and I'm not going to this time. However, at the Bush Centre we are speaking up."

A spokesman for the former President previously told People magazine that neither he nor the former first lady voted for Trump or for Democratic nominee Hillary Clinton in the November 8 election. 

The couple cast write-in votes for a candidate they did not reveal.