President Donald Trump took a swing at his predecessor on Monday, declaring on Twitter that his first 90 days in office have 'exposed the total failure' of Barack Obama's foreign policy.

Trump was repeating a claim that conservative author Michael J. Knowles had made on Fox & Friends about the 'total failure of the last eight years of foreign policy.'

'A great book for your reading enjoyment: "REASONS TO VOTE FOR DEMOCRATS" by Michael J. Knowles,' Trump said afterward, endorsing Knowles' empty book.

President Donald Trump took a swing at his predecessor on Monday, declaring on Twitter that his first 90 days in office have 'exposed the total failure' of Barack Obama's foreign policy

Trump was repeating a claim that conservative author Michael J. Knowles had made on Fox & Friends

Knowles had made a similar claim during an interview on the program

An Amazon bestseller, Knowles' book claims to be the 'most exhaustively researched and coherently argued Democrat Party apologia to date.' Its 266 pages are blank, except for the title of the book, listed on each page.

Asking price on Amazon for the sold-out first edition currently ranges $162.00 to $220.01.

A second edition of the book dropped on April 11 and is selling at the original paperback price point of $9.99 for a new copy on Amazon.

Knowles was on Fox & Friends this morning to talk about the reception his book, published in February, has received.

Questioned by Fox host Brian Kilmeade about the section on 'foreign policy' and whether the 'last eight years are being exposed right now, Knowles said: 'It is unbelievable how within the first 100 days of this presidency we have exposed the total failure of the last eight years of foreign policy.

'And it really is, I think – I think people on both sides of the aisle are seeing that there is a real breath of fresh air coming in,' the Daily Wire author said.

Trump responded with an endorsement of the book and a tweet backing up Knowles' claim.

' "The first 90 days of my presidency has exposed the total failure of the last eight years of foreign policy!" So true,' he said.

Knowles was on Fox & Friends this morning to talk about the reception his book, published in February, has received

An Amazon bestseller, Knowles' book claims to be the 'most exhaustively researched and coherently argued Democrat Party apologia to date.' It is blank

Trump has bombed Syrian dictator Bashar al-Assad's army and ISIS in Afghanistan since taking office. He warned North Korea repeatedly last week that its missile tests are a 'problem' and he will take military action, there, too, if he feels that he has to.

'Between the airstrikes in Syria and Afghanistan, this administration has made very clear that it will take action when it feels it is appropriate,' Kellyanne Conway, senior counselor to the president said in Monday morning Fox & Friends segment.

Vice President Mike Pence proclaimed early this morning that 'the era of strategic patience is over' during a visit to South Korea during which he pledged the United States 'unwavering support' to the North Korean neighbor.

'We are with you 100 percent,' he said, assuring the United States' ally is 'ironclad.'

Several minutes after Trump's initial tweets, the president also hit the 'fake media' for writing unflattering stories about his administration. He accused unnamed outlets of anti-Trump bias.

'The Fake Media (not Real Media) has gotten even worse since the election. Every story is badly slanted. We have to hold them to the truth!' he said.

Several minutes after Trump's initial tweets, the president also hit the 'fake media' for writing unflattering stories about his administration. He accused unnamed outlets of anti-Trump bias

A reoccurring theme in the president's messaging, Trump's son Eric opined on Fox & Friends later in the morning about the same subject.

In an interview from the South Lawn of the White House during the annual Easter Egg Roll, Eric Trump told Fox & Friends host Ainsley Earhardt the coverage of his sister and brother-in-law has been unfair.

'Sometimes no good deed goes unpunished,' he said of their unpaid jobs in the White House. 'It's very unfortunate...They both have hearts of gold. I mean, they are amazing, amazing people, and they wanted to help. They wanted to do a great thing.

Jared and Ivanka 'are going to be amazing advisers to my father, and they are going to represent this country incredibly, incredibly well,' he added.