Ben May of Oxford Economics said: "Economic theory would suggest that if you raise your interest rates that it is likely to lead to a stronger currency. But to a certain degree you can't explain currency movements with one side of an argument. More often than not it's going to be a combination of events."
Mounting political tensions will have made safe haven currencies more attractive, but May said, "Russia is clearly not a safe haven in this context."
Trump's social media post may also be a thinly veiled critique of Jerome Powell, the head of the Federal Reserve and top interest rate-setter, who said that the US government was not on a "sustainable fiscal path".
The tweet also comes after Japan lent its support to free trade, following highly unusual meetings between Taro Kono, Japan's foreign minister, and Wang Yi, the Chinese government's top diplomat.
The meetings were the first of their kind for seven years and have been held less than a week before talks between Prime Minister Shinzo Abe and President Trump.
Kono said: "We have shared understanding that a trade war ... would have a very large impact on the prosperity of the international economy."
Japan's backing of China's bid to raise support for free trade and the supremacy of the WTO in settling disputes comes amid rising concerns about the US pressure for a bilateral Japan-US trade deal.
Trump has raised the possibility of rejoining the Trans Pacific Partnership. Some believe that the move was an attempt at turning the screws on Tokyo ahead of talks this week.