WASHINGTON (REUTERS) - President Barack Obama's pick for CIA director, Mr John Brennan, promised senators who will vote on his nomination more openness about US counter-terrorism programmes, saying the closely guarded number of civilian casualties from drone strikes should be made public, according to his written responses to questions released on Friday.

Mr Brennan was questioned sharply by Democrats and Republicans alike during a Senate Intelligence Committee hearing on his nomination last week.

Along with harsh interrogation techniques, Mr Brennan was questioned about drone strikes against terrorism suspects in Pakistan, Afghanistan, Yemen and elsewhere. These strikes have increased under Mr Obama and included the killing in Yemen of a US-born cleric suspected of ties to Al-Qaeda and his US-born son.

The US government, without releasing numbers, has sought to portray civilian deaths from these strikes as minimal. But other organisations which collect data on these attacks put the number of civilians killed in the hundreds.

"I believe that, to the extent that US national security interests can be protected, the US government should make public the overall numbers of civilian deaths resulting from US strikes targeting Al-Qaeda," Mr Brennan wrote in response to a question from Senator Dianne Feinstein, the committee chairwoman.

"In those rare instances in which civilians have been killed" reviews are conducted and, if appropriate, condolence payments are provided to the families, he wrote.

Such casualties from drone strikes have created profound anger among civilian populations overseas and severe tension between the United States and Pakistan and Afghanistan.

During last week's hearing, Ms Feinstein said she had been trying to speak publicly about the "very low number of civilian casualties" and to verify that number each year has "typically been in the single digits". However, she said she was told she could not divulge the actual numbers because they were classified.

The New America Foundation said the number of civilians killed by US drone strikes in Pakistan was 261 to 305 from 2004 to 2013.

A former intelligence official said the reason for the discrepancy between the US government's apparently lower figures on civilian deaths and those collected by other organisations may be due to what is counted as a civilian death.

The government assumes "military-aged" males in the proximity of a drone strike are combatants unless it finds out otherwise, the former official said.

Asked whether the government could carry out drone strikes inside the US, Brennan replied: "This administration has not carried out drone strikes inside the United States, and has no intention of doing so."

US legal authorities have not limited the geographic scope to a war zone for using force against Al-Qaeda and its affiliates, he noted, adding: "This does not mean, however, that we use military force whenever or wherever we want."