Wall Street was mixed, even as the Dow hit a fresh record high, amid disappointing corporate earnings such as from Qualcomm and Caterpillar.
The Mexican peso fell after President Pena Nieto cancelled a meeting with his US counterpart, Donald Trump, as tensions between the two countries grew over the latter's plan to build a border wall.
The US dollar strengthened. Even so, its gains may be limited in the months ahead.
"Markets were very long dollars heading into year-end and the prevailing assumption was that it was clearly going to the moon," Ned Rumpeltin, the European head of foreign-exchange strategy at Toronto Dominion Bank, told Bloomberg. "It was inevitable for the pendulum to swing back."
"What is interesting is that the dollar has been still on a weak footing while real rates appear to have bottomed," Rumpeltin noted. "That suggests that positioning remains a key element near term."
Wall Street seesawed. In 1.02pm trading in New York, the Dow traded 0.15 per cent higher, while the Nasdaq Composite Index eked out a 0.01 per cent gain. In 12.50pm trading, the Standard & Poor's 500 Index slipped 0.08 per cent.
The Dow rose as high as a record 20,125.58 earlier in the session.
The Dow moved higher as gains in shares of UnitedHealth Group and those of DuPont, up 1.5 per cent and 1.1 per cent respectively, outweighed declines in shares of Verizon and those of United Technologies, recently 1.5 per cent and 1 per cent lower respectively.
Shares of Caterpillar slid after the company posted a disappointing outlook, citing a challenging economic environment.
The company predicted sales and revenues in 2017 of between US$36 billion and US$39 billion with a midpoint of US$37.5 billion, it said in a statement. Caterpillar reported full-year sales and revenues in 2016 of US$38.5 billion, down about 18 per cent from US$47.0 billion in 2015.
The lowered outlook "is happening because business still stinks," Stephen Volkmann, a New York-based analyst for Jefferies, told Bloomberg.
"The recovery is certainly not happening yet."
Shares of Caterpillar slid 1 per cent as of 12.21pm in New York.
Markets were very long dollars heading into year-end and the prevailing assumption was that it was clearly going to the moon.
"We continue to execute in a challenging economic environment and are focused on improving operating margins, profitability and shareholder returns," Caterpillar Chief Executive Officer Jim Umpleby said in the statement.
"While we see signs of positive activity in some of our key end markets, the overall economic environment remains challenging."
There were other disappointments.
Shares of Qualcomm fell, last 6 per cent weaker, after the chipmaker posted quarterly revenue that grew less than expected.
Shares of Canada's Potash Corp of Saskatchewan slid after the producer of fertiliser reported quarterly earnings and an outlook that fell short of expectations amid weaker crop nutrient prices.
The stock traded 3.5 per cent weaker in Toronto as of 11.52am.
In Europe, the Stoxx 600 Index ended the day with a 0.3 per cent advance from the previous close. Germany's DAX Index added 0.4 per cent.
However, the UK's FTSE 100 Index slipped 0.04 per cent, while France's CAC 40 Index fell 0.2 per cent.
Shares of Switzerland's Actelion soared 19 per cent after Johnson & Johnson agreed to buy the drugmaker for US$30 billion.