President Donald Trump lashed out again at U.S. allies Canada and Europe on trade in a Monday morning Twitter post.

The U.S. leader, who is now in Singapore to meet with his North Korean counterpart, said "Fair Trade is now to be called Fool Trade if it is not Reciprocal," and called into question the trading relationship between his country and some of its closest allies.

Trump tweet: Fair Trade is now to be called Fool Trade if it is not Reciprocal. According to a Canada release, they make almost 100 Billion Dollars in Trade with U.S. (guess they were bragging and got caught!). Minimum is 17B. Tax Dairy from us at 270%. Then Justin acts hurt when called out!

Trump followed up that message with another tweet:

Trump tweet: Why should I, as President of the United States, allow countries to continue to make Massive Trade Surpluses, as they have for decades, while our Farmers, Workers & Taxpayers have such a big and unfair price to pay? Not fair to the PEOPLE of America! $800 Billion Trade Deficit...

The president also claimed that the U.S. is responsible for most of the cost of the inter-governmental military alliance, the North Atlantic Treaty Organization, to protect "the many of these same countries that rip us off on Trade."

Trump tweet: And add to that the fact that the U.S. pays close to the entire cost of NATO-protecting many of these same countries that rip us off on Trade (they pay only a fraction of the cost-and laugh!). The European Union had a $151 Billion Surplus-should pay much more for Military!

About an hour after the series of Twitter posts, Trump reiterated his message in another tweet:

Trump tweet: Sorry, we cannot let our friends, or enemies, take advantage of us on Trade anymore. We must put the American worker first!

Trump has been lashing out at Canadian Prime Minister Justin Trudeau since Saturday after he refused to endorse the G-7 declaration calling for a reduction in various barriers to trade, including tariffs.

He slammed Trudeau in a Twitter post for being "very dishonest & weak" after Trudeau held a news conference that called the U.S. tariffs "kind of insulting."

White House economic advisor Larry Kudlow also accused Canada of making "polarizing" statements about the United States' trade policy, and said Trump had to pull out of a joint statement because his Canadian counterpart had "stabbed us in the back."