WASHINGTON (Reuters) - Seven U.S. senators urged Secretary of State John Kerry on Thursday to press Bahrain’s government to do more to promote political and social reform, adding to recent concern in Washington over that country’s human rights record.

The letter said the United States should be prepared to consider “tangible consequences,” including reconsidering arms sales, if a recent crackdown on opposition continues.

“Bahrain’s failure to address the legitimate grievances of its citizens has strained the country’s social fabric and invited outside actors to take advantage of the deteriorating situation,” six Democratic lawmakers and one Republican said in a letter to Kerry, a former Democratic senator.

“Indeed, we believe the government’s harsh crackdown on the political opposition undermines the country’s stability and plays into the hands of Iran,” they wrote, calling themselves “deeply alarmed.”

State Department spokesman John Kirby said he was aware of reports about the letter, but had not seen it.

Asked about whether U.S. arms provided to Bahrain could be used against the opposition, he said, “We always have concerns about the end use of items that are inside the foreign military sales program.”

Bahrain, which hosts the United States’ Fifth Fleet and is seen by Sunni-ruled Gulf kingdoms as a strategic bulwark against Iranian influence, drew U.S. and United Nations criticism this month when it moved to strip a top Shi’ite cleric’s citizenship and closed the main Shi’ite opposition group.

A State Department report, first reported by Reuters, found Bahrain’s national reconciliation efforts after it crushed street protests in 2011 have stalled, and said the Western ally in the Gulf has not implemented recommendations to protect freedom of expression.

“We continue to urge the government of Bahrain to reverse their recent harmful actions,” Kirby said a news briefing on Thursday.

Earlier this week, the State Department said Bahrain’s plan to try an activist for tweets condemning its prison system and involvement in the war in Yemen is worrisome to the United States.

The letter was led by Democratic Senator Chris Murphy and also signed by Republican Marco Rubio and Democrats Patrick Leahy, Ron Wyden, Bob Casey, Chris Coons and Tim Kaine.

It asked for more information on specific actions President Barack Obama’s administration is taking to press Bahrain’s leadership on the issue.