PRECIOUS-Gold heads for best week in more than a month on US fiscal worries

May 23 (Reuters) - Gold was on track for its best weekly gain in over a month on Friday, as a softer dollar and mounting concerns about the deteriorating fiscal outlook of the world's biggest economy boosted the metal's safe-haven appeal.

FUNDAMENTALS

* Spot gold XAU= gained 0.2% to $3,299.79 an ounce as of 0014 GMT. Bullion is up about 3% so far this week and on track for it best weekly performance since early April.

* U.S. gold futures GCcv1 rose 0.2% to $3,299.60.

* The dollar .DXY has lost more than 1% so far this week and is set for its worst weekly performance since April 7, making greenback-priced gold cheaper for holders of other currencies.

* The Republican-controlled U.S. House of Representatives passed a sweeping tax and spending bill on Thursday, embedding much of President Donald Trump's policy agenda and adding trillions of dollars more to the national debt.

* What Trump dubbed a "big, beautiful bill", is now headed to the Senate, which Republicans control by a 53-47 margin.

* On Wednesday, the U.S. Treasury Department saw soft demand for a $16 billion sale of 20-year bonds. Investor sentiment was already fragile after Moody's downgraded the U.S. triple-A credit rating last week.

* Gold is used as a safe store of value during political and financial uncertainty.

* Meanwhile, Iran's Foreign Minister Abbas Araqchi warned that the U.S. would bear legal responsibility for any Israeli attack on Iranian nuclear facilities, following a CNN report that Israel is preparing strikes on Iran.

* Spot silver XAG= was steady at $33.07 an ounce, platinum XPT= rose 0.1% to $1,082.47 and palladium XPD= lost 0.3% to $1,012.00.

DATA/EVENTS (GMT)