(Reuters) - U.S. bank Citigroup ( C/PN ) said on Tuesday it is exiting the Net-Zero Banking Alliance (NZBA), a group of global banks that have pledged to curb greenhouse gas emissions.

This move makes Citigroup ( C/PN ) the third major U.S. lender to exit the group after Wells Fargo ( WFC ) and Goldman Sachs ( GS ), which both left earlier this month.

Financial firms, historically criticized for their connections to the fossil fuel industry, have made efforts to incorporate net-zero standards more prominently into their operations.

However, they have begun scaling back on some initiatives to avoid irking Republican policymakers who are opposed to limiting the financing of fossil fuels.

Citi said it had made progress towards its own net-zero goals and decided to leave the NZBA.

The NZBA aims to bring down carbon emissions from the lending and investment portfolios of its members to zero on a net basis by 2050.

Last month, BlackRock ( BLK ) , Vanguard and State Street were sued by Texas and 10 other Republican-led states, which said the large asset managers violated antitrust law through climate activism that reduced coal production and boosted energy prices.