WASHINGTON (Reuters) - The U.S. government needs to improve and accelerate its process for approving foreign arm sales, Senator John McCain said Thursday, warning that U.S. firms were losing billions of dollars of potential orders to countries like Russia.

U.S. Senator John McCain speaks at the Munich Security Conference in Munich, Germany, February 14, 2016. REUTERS/Michael Dalder

McCain, who heads the powerful Senate Armed Services Committee, said both the White House and State Department were too slow to process requests for arms sales from U.S. allies and coalition partners, noting he frequently received complaints from visiting defense ministers.

“We need to streamline that process, perhaps even with legislation. It’s not working,” McCain told reporters. “These countries deserve a decision. If it’s no, it’s no. If it’s yes, it’s yes.”

Any legislative changes would be led by the Senate Foreign Relations Committee, which oversees foreign military sales, McCain said. He said Senator Bob Corker, who heads that committee, had also expressed frustration about arms sales delays.

McCain noted that Saudi Arabia, United Arab Emirates and Qatar had recently purchased billions of dollars worth of equipment from Russia while waiting for potential U.S. arms sales to be processed.

U.S. government officials say efforts to reform the arcane U.S. export control regime are starting to pay off but acknowledge that they have more work to do to cope with the current record level of U.S. foreign military sales and to improve the often sluggish approval process.

McCain said it was important for the United States to continue supporting Israel, which had traditionally expressed reservations about large arms sales to Middle Eastern countries.

But changing realities in the Middle East made it important to ensure that countries in the region had the equipment they needed to engage in actual fighting, he said. He said Israel was also relaxing its concerns given that it was facing the same enemy - Iran - as countries with a Sunni Muslim majority.

McCain and other lawmakers have expressed particular frustration about two Boeing Co arms sales - an F-15 fighter jet sale to Qatar and an F/A-18E/F sale to Kuwait - that have stalled as the Obama administration focuses on concluding on a long-term military funding agreement with Israel.

Reuters reported earlier this month that Boeing is nearing a decision to spend hundreds of millions of dollars to preserve its F/A-18 fighter jet line and start work on 28 F/A-18 fighter jets for Kuwait while it waits for the Obama administration to approve the deal.