"Obviously, the short-term issues of the dollar have both positive and negative impacts for different parts of the economy," Mnuchin said in an interview on "Squawk Alley." "Obviously, as it relates to trade, having a weaker dollar is somewhat better for us."
A strong U.S. currency gives Americans more purchasing power. However, it also makes U.S.-produced goods more expensive in global markets.
The U.S. dollar has been considerably weaker this year. The dollar index, which measures the greenback against a basket of six major rivals, is down about 10 percent year to date. Since the election, it's down 5.32 percent.
In April, President Donald Trump told The Wall Street Journal the dollar was "getting too strong."
And this month, he told the Journal: "I like a dollar that's not too strong."
Mnuchin said Thursday he's consistently said the dollar's short-term level is less of a concern for him.
"I do think over long periods of time, the dollar's strength is an indication of the reserve currency and the confidence people have in the U.S. economy," he said.
Mnuchin also told CNBC the administration has a "very detailed" tax plan ready and "couldn't be more excited" about its prospects.