WASHINGTON (Reuters) - The United States is concerned about the physical well-being of hunger-striking activists in Cuba and is closely watching their situation, the U.S. State Department said on Friday.

"We stand in solidarity with those who advocate for human rights and fundamental freedoms, including freedom of expression and the right to peaceful assembly," State Department spokesman John Kirby told a briefing.

"We have raised our concerns directly with the Cuban government, both in Washington and Havana," he added.

Kirby said Washington was particularly concerned about the health of dissidents Carlos Amel Oliva, who leads the youth wing of a Cuban dissident group, and Guillermo Farinas.

Farinas began a hunger strike earlier this month calling, for Raul Castro's government to end torture and human rights abuses. He was taken to Arnaldo Milian Castro Hospital in the city of Santa Clara on Thursday after becoming extremely weak and fainting eight days into the strike, The Miami Herald reported.

Farinas and about 20 other rights activists are on hunger-strike in Cuba.

(Reporting by Arshad Mohammed; Writing by David Alexander; Editing by Sandra Maler)