U.S. stocks notched weekly gains as investors digested latest remarks from Federal Reserve Chair Janet Yellen as well as the country's major economic data.

At the annual Economic Policy Symposium in Jackson Hole on Friday, Yellen said that the financial system is safer now than it was during the 2008 financial crisis, though some adjustments may be needed to regulations.

However, Yellen offered no clues about the future of the country's monetary policy.

Expectations for tighter monetary policy in the U.S. have been dampened recently by soft inflation data. Market expectations for a rate hike in December are just 39.9 percent, according to the CME Group's FedWatch tool.

Meanwhile, investors kept an eye on the prospects of the U.S. tax reform. U.S. President Donald Trump will start campaigning for long-waited tax reform next week, according to his chief economic advisor Gary Cohn.

"Starting next week, the president's agenda and calendar is going to revolve around tax reform," Cohn said in an interview with Financial Times published Friday.

"He will start being on the road making major addresses justifying the reasoning for tax reform and why we need it in the U.S." he said.

But Wall Street was still concerned about political uncertainty in the White House.

Trump announced earlier this month that he was disbanding both the Manufacturing Council and Strategy and Policy Forum, as business leaders resigned from the council over his remarks on Charlottesville violence.

Analysts said recent turmoil in Washington spurred market concerns about whether the Trump administration is able to push through its economic agenda.

On the economic front, new orders for manufactured durable goods in July decreased 6.8 percent to 229.2 billion U.S. dollars, the U.S. Commerce Department announced Friday, missing market consensus. This decline, down three of the last four months, followed a 6.4 percent June increase.

U.S. Labor Department reported on Thursday that in the week ending August 19, the advance figure for seasonally adjusted initial jobless claims was 234,000, an increase of 2,000 from the previous week's unrevised level of 232,000. The 4-week moving average was 237,750, a decrease of 2,750 from the previous week's unrevised average of 240,500.

Sales of new single-family houses in July were at a seasonally adjusted annual rate of 571,000, according to U.S. Commerce Department on Wednesday, missing market expectations. The latest reading was also 9.4 percent below the revised June rate of 630,000 and is 8.9 percent below the July 2016 estimate of 627,000.

For the week, the blue-chip Dow added 0.6 percent and the broader S&P 500 gained 0.7 percent, while the tech-heavy Nasdaq increased 0.8 percent.