July 3 (Reuters) - Rhode Island's Democratic governor, Lincoln Chafee, has signed a bill to increase the state's minimum wage by $1, to $9 an hour, his office said on Thursday, following similar moves by neighboring New England states.

The hike, which will take effect next year, comes as Democrats across the country have made raising the minimum wage a key priority ahead of November's elections, saying wages for millions of Americans have not kept pace with the rising cost of living.

"Our entire economy suffers when the middle class and low-wage earners can't make ends meet," Rhode Island state Representative David Bennett, a Democrat who sponsored the bill, said in a statement. "This raise will provide some measure of assistance for those struggling at the low end of the pay scale."

Rhode Island joins nine other states and the District of Columbia, including neighboring Connecticut and Vermont, in passing state minimum wage increases during the 2014 legislative session, according to the National Conference of State Legislatures.

Last week, Massachusetts Governor Deval Patrick signed a law that will raise the state's minimum wage to $11 per hour by 2017, the highest level of any U.S. state.

In addition, last month, the Seattle City Council approved a sharp hike in the city's minimum wage to $15 an hour over the next seven years. Seattle was the first major U.S. city to commit to such a high base level of pay.

President Barack Obama proposed raising the federal minimum hourly wage from its current $7.25 to $10.10 per hour during the next three years, but the idea failed to win support in either the Republican-controlled House of Representatives or the Democratic-controlled Senate, with opponents saying an increase would cost jobs. (Reporting by Curtis Skinner in New York; Editing by Edith Honan and Eric Beech)