The tweets come a day after multiple sources reported that Trump is "obsessed" with Amazon and wants to "go after" the e-commerce giant - a report that caused Amazon's shares to fall nearly 5% and wiped out more than $31B in shareholder value in the process.
Amazon could hurt the postal service - and other package companies - if it successfully shifts more of its delivery to its own delivery network, which it's been slowly building out over the past few years.
As with many Trump claims, saying the company doesn't pay taxes despite making billions in profits is a misleading conclusion based on a shred of truth. "We have no announcements and no specific policies or actions that we're now pushing forward or considering taking", she said.
"If there really was teeth or real concern that something would come out of the government and regulatory oversight, Amazon's stock drop would be a lot lower than it is today", said Robert Bacarella, portfolio manager at Monetta Financial Services in Wheaton, Illinois, which holds Amazon shares. In the 2017 fiscal year, the agency reported a net loss of $2.7 billion; the previous three years, it incurred losses of almost twice that amount.More news: NHL: Bruins beat Lightning to take over 1st in the East
"The red herring in this story was on state-level taxes", Toronto Region Board of Trade president Jan De Silva told CBC News in an interview".
However, "Amazon is continuing to drag its feet rather than collecting taxes on the "marketplace" portion of its business, where it partners with third-party sellers", said Carl Davis, research director at the Institute on Taxation and Economic Policy.
The online retailer has been continuously adding products which are ready to be shipped for next day or two day deliveries.
In another financial report previous year, USPS said growth in its package business was "a result of our successful efforts to compete in the ground shipping services and "last mile" e-commerce fulfillment markets, including Sunday delivery".
Donald Trump has long expressed negativity towards Amazon and its founder, Jeff Bezos. "Unlike others, they pay little or no taxes to state and local governments, use our Postal System as their Delivery Boy (causing tremendous loss to the US), and are putting many thousands of retailers out of business!", Trump said in a tweet.More news: LeBron James on Lue approaching return: 'We starting to get full'
White House spokeswoman Sarah Sanders said Wednesday no specific policies were now being considered in regards to Amazon. Third party sellers have been crying foul over these sellers getting preferential treatment from the company but Amazon has always maintained it treats every merchant on its platform under the same policy.
The report claims that the president's wealthy, real estate friends are telling him that Amazon is killing traditional shopping malls and high street retailers.
To comply with federal law, the Postal Service in 2017 had to generate at least $1.6 billion in income from its "competitive nonpostal services", which includes Amazon package deliveries.
"During the previous five years, Amazon reported US profits of $8.2 billion and paid an effective federal income tax rate of just 11.4 percent", wrote Matthew Gardner, an ITEP senior fellow. But there are other factors, such as high debt, and Amazon is not exclusively responsible.
White House Deputy Press Secretary Raj Shah denied on Thursday that Trump's criticism was a personal grudge.More news: Chelsea v Tottenham Premier League Preview
The official said Trump links this to Amazon Chief Executive Jeff Bezos' private ownership of the Washington Post, which he has called "fake news" and effectively a mouthpiece for Bezos' business interests. "It's really about policy".