Rometty sits on President Donald Trump's business advisory board and was among a group of U.S. and German leaders who met with the President and German Chancellor Angela Merkel Friday.
"As part of the advisory board, we have been very clear about things like tax reform," she said. "Some of the most important things are to modernize the tax system, both from a rate perspective and a territorial system."
Workforce retraining will also be central to achieving Trump's economic growth agenda, and was a topic at last Friday's White House meeting, Rometty said. There are 5.5 million job openings in the U.S., half a million of which are in tech, she said.
Rometty spoke with CNBC from the company's cloud conference, IBM Interconnect, in Las Vegas Tuesday. IBM's Cloud business accounts for 17 percent of the company's overall revenue, according to the company. Its cloud business grew 35 percent in 2016 to deliver $13.7 billion in revenue.
Rometty has been steering Big Blue toward areas such as cloud-based services, security software and data analytics, while trimming its traditional hardware business by exiting low-margin businesses. New customers include AT&T, Salesforce, H&R Block and the Royal Bank of Canada.
Still, IBM has seen 19 straight quarters of declining year-over-year total revenues. IBM is valued around $165 billion and on average, analysts recommend holding the stock.