Analysts said the proposal put forth by US House Republicans was unlikely to gather sufficient support in Congress and unlikely to have significant impact on the US economy. "Massive" tax cuts had been a major campaign promise of US President Donald Trump.
Markets in Mexico and Brazil, Latin American's two biggest economies, remained closed on Thursday due to local holidays.
Mexico's peso gained 0.83 percent to 18.9250, following its worst monthly loss in around a year in October.
In Chile, the peso gained 0.86 percent to 629.80 on the back of the weaker dollar and stronger prices for top export copper.
Meanwhile, the Colombian peso jumped 1.21 percent to 3027.8.