The administration of US President Barack Obama has said it will resume some arms shipments to Bahrain after most were suspended last year during a government crackdown on political dissent.
The state department said on Friday the administration still has human rights concerns about its strategic Gulf ally and will work with the government to improve the situation but that equipment for Bahrain's "external defence" would be released because it is in US national interests.
Bahrain hosts the US navy's 5th Fleet.
"Bahrain is an important security partner and ally in a region facing enormous challenges,'' State Department spokeswoman Victoria Nuland said in a statement.
Maintaining the ability to respond to such challenges is a critical part of the US commitment to Gulf security, she said, adding that the administration is "mindful'' of "serious unresolved human rights issues'' and that some items, such as TOW anti-tank missiles and Humvees, would still not be delivered.
Among the equipment being released are harbor patrol boats for the Bahrain Coast Guard and upgrades to F-16 fighter engines, officials said. They did not give an estimate of cost of the items, but the package suspended last year was worth $53 million.
Nuland stressed that items being released are not used for crowd control and that the United States remains concerned about excessive use of force and tear gas against protesters demanding reforms.
Officials said tear gas, tear gas launchers and stun grenades are not included in the package, but human rights activists denounced the move.
"This sale is completely out of step with the United States' stated commitment to reform in Bahrain,'' said Brian Dooley of Human Rights First. "Where is the progress that warrants the reward of arms? This new sale will only damage US credibility among those working for democracy in Bahrain and across the Middle East.'
Friday's announcement followed a visit to Washington DC by Bahraini Crown Prince Salman bin Hamad Al Khalifa, perceived as a voice for reform in the ruling Khalifa family. Salman met with Vice President Joe Biden, Secretary of State Hillary Rodham Clinton and Defence Secretary Leon Panetta.
But it also came on the same day that Bahraini riot police fired tear gas and stun grenades during clashes with anti-government protesters following a rally calling for the release of detained activists, according to witnesses.
At least 50 people have died since unrest began in February 2011 amid widespread anti-authoritarian protests in the Arab world.
Though the Obama administration included criticism of protesters for violence, officials also said the government must reform.
In his meeting with the crown prince on Friday, Biden expressed concern about the recent escalation of street violence, including attacks against security forces, according to a White House statement.
The vice president stressed "the importance of ensuring fundamental rights for all Bahrainis and the need for greater progress by the government on accountability for past abuses, police reform and integration, and inclusive political dialogue,'' the statement read.
Nuland praised Bahrain's government for taking "some important steps'' to follow through on recommendations made by a special commission created to look into the violence.
But she added that much more work must be done to ease increasing polarisation between the majority Shia Muslim community and the ruling Sunni monarchy.
And she lamented that some protesters were resorting to violence.
"We urge all sides to work together to end the violence and refrain from incitement of any kind, including attacks on peaceful protesters or on the Bahraini police,'' Nuland said.