NEW YORK (Reuters) -S&P Global Ratings' decision to affirm its U.S. credit rating reflected the impact of tariff revenues, but questions remain on the economic outcome of U.S. trade policies that could influence the country's rating in the next few years, the primary analyst on the U.S. said.

S&P on Monday affirmed its "AA+" credit rating on the U.S., saying the revenue from President Donald Trump's tariffs has the potential to offset the fiscal hit from his massive tax-cut and spending bill. S&P, which became the first ratings agency to cut the pristine U.S. government rating in 2011, said the outlook on the U.S. rating remains stable.

"Outcomes are what's really going to weigh and inform the rating," Lisa Schineller, primary U.S. analyst at S&P Global Ratings, said in an interview.

"The outcomes of how you execute the budgetary legislation, how the tariff revenue comes, their combined impact on growth and investment that leads to either better or worse or similar fiscal out-turns, that's our focus," she said.