Washington - Fake news or fib?Two phone calls described by President Donald Trump that didn't actually happen represent the latest chapter in a long-running series of disputes revolving around the president's rocky relationship with facts.White House press secretary Sarah Sanders on Wednesday found herself explaining that compliments Trump had described receiving in phone calls from the Mexican president and the Boy Scouts did happen - just not on the phone."I wouldn't say it was a lie. That's a pretty bold accusation," she told reporters. "The conversations took place, they just simply didn't take place over a phone call. ... He had them in person."The non-calls weren't earth-shattering news. But they fit a pattern that also involves weightier issues and that has raised larger questions about Trump's credibility six months into his presidency.After Donald Trump jnr put out a statement, later shown to be misleading, about his meeting with a Russian lawyer in 2016, the president's outside lawyer was categorical that the president had no role in drafting the statement. But when The Washington Post later reported that the president had dictated the statement for his son, Sanders acknowledged that Trump had "weighed in" on his son's statement "as any father would based on the limited information that he had".Job approvalPolls, history and other research leave open the question of how impressions of Trump's truthfulness affect his job approval, which hovers around a third of Americans.Trump won the presidential election despite having promoted false claims such as the notion that president Barack Obama was born outside the US (he was born in Hawaii) and that Hillary Clinton had started the rumour (she didn't).The campaign featured another instance when Trump said someone told him something that the person then denied. Candidate Trump last summer claimed the NFL had complained to him that the presidential debate schedule competed with football games. The NFL denied that.A Quinnipiac poll released on Wednesday found that for all of the economic and other progress Trump claims, just 33% of Americans approve of the job he's doing, similar to the results of a survey conducted in June by the Associated Press-NORC Center for Public Affairs Research.Only 34% of the Quinnipiac poll respondents say that Trump is "honest"."We've been through so much of this," said Ethan Porter, an assistant professor of media and public affairs at George Washington University, who co-authored a study released last month into whether false information and corrections change people's attitudes toward candidates. In Trump's case, he said, "People probably learned to discount additional instances" of falsehoods, adding: "It's already baked in the cake where you sort of know what you're getting with Donald Trump at this point."Sanders was responding to questions about a statement from the Mexican government denying what Trump described as a recent phone call with Mexican President Enrique Pena Nieto. Trump said earlier this week that Pena Nieto had called him to praise his immigration policies.G-20 summit"Even the president of Mexico called me. They said their southern border, very few people are coming because they know they're not going to get through our border, which is the ultimate compliment," Trump said on Monday.Sanders said Trump had been "referencing a conversation that they had had at the G-20 summit where they specifically talked about the issues that he referenced".Mexico's Foreign Relations Department said Pena Nieto remarked to Trump during a July 7 meeting at the G-20 summit in Germany that deportations of Mexicans from the United States had fallen 31% between January and June, as compared with 2016. Pena Nieto said 47% fewer Central American migrants had entered Mexico in that period.Boy ScoutsMeanwhile, the Boy Scouts denied on Wednesday that the head of the youth organisation called Trump to shower praise on his politically aggressive speech to its national jamboree in West Virginia. President Randall Stephenson and Chief Scout Executive Mike Surbaugh later apologised to members of the scouting community who were offended by Trump's political rhetoric.Trump told The Wall Street Journal in an interview last week, "I got a call from the head of the Boy Scouts saying it was the greatest speech that was ever made to them, and they were very thankful." Politico published the transcript of the interview on Tuesday.Sanders said the president was making reference to "multiple members of the Boy Scout leadership" who "congratulated him, praised him and offered quite powerful compliments following his speech."