NEW YORK (AFP) - Wall Street stocks finished mostly higher on Wednesday (Dec 16), with the Nasdaq setting a fresh record, as markets cheered progress on US stimulus talks and a dovish Federal Reserve announcement.

Congressional leaders said they were nearing a long-awaited agreement on a stimulus package for the pandemic-hit US economy, with top Senate Democrat Chuck Schumer describing the parties as "very close" to a deal.

That helped lift the Nasdaq to a second straight record, closing at 12,658.19, a gain of 0.5 per cent.

The Dow Jones Industrial Average shed 0.2 per cent to end the day at 30,154.54, while the broad-based S&P 50 climbed 0.2 per cent to 3,701.17.

Progress on the stimulus package helped offset disappointment over the November retail sales report, which fell by a bigger-than-expected 1.1 per cent compared to October in a sign of the drag from higher coronavirus cases.

Investors also took heart from a slightly upgraded Fed forecast for US growth in 2021 and 2022 as the central bank maintained ultra-low interest rates.

"The case for fiscal policy right now is very strong. I think that is widely understood," Fed chairman Jerome Powell told reporters following the central bank's two-day policy meeting, noting that expanded jobless benefits and eviction moratoriums are set to expire before the end of the year.

Sam Stovall, chief investment strategist at CFRA Research, said the US equity market "appears to be traveling on end-of-year auto-pilot, which should allow share prices to drift higher, unless they hit an unanticipated pothole."

Among individual companies, Pfizer fell 2.2 per cent following a report that a health worker in Alaska suffered a serious allergic reaction after getting Pfizer-BioNTech's Covid-19 vaccine and is now hospitalised but stable.

Twitter jumped 2.3 per cent after a JPMorgan Chase note lifted its price forecast for the microblogging company.