Russia is the biggest threat to US national security and America must boost its military presence throughout Europe even as Nato allies face budget challenges and scale back spending, the US air force secretary, Deborah James, said on Wednesday.



“I do consider Russia to be the biggest threat,” James said in an interview after a series of visits and meetings with US allies across Europe, including Poland.

James said Washington was responding to Russia’s recent “worrisome” actions by boosting its presence across Europe, and would continue rotational assignments of F-16 fighter squadrons.

“This is no time to in any way signal a lack of resolve in the face of these Russian actions,” she said.

James said she was disappointed that only four of Nato’s 28 members had thus far met the Nato target of spending 2% of gross domestic product on defense.

“This is not something that came up out of thin air. This is something that we as NATO members agreed to do. All of us need to be advocates,” she said.

The top air force civilian leader acknowledged that Europe was facing difficult immigration and economic challenges at the moment, but said the Nato military alliance and associated commitments should be a clear priority.

Britain on Wednesday said it would commit to the 2% spending pledge for the next five years, which will raise the number of Nato allies meeting the spending goal to five in 2015.

Given the tensions, the air force is continuing its effort to reduce US reliance on Russian RD-180 rocket engines for military and intelligence satellite launches, James said.

She said there were huge demands on US air force assets now, given the tensions with Russia and the fight against Islamic State, but the air force was also working hard to defend its weapons systems and networks against growing cyber attacks.

James said her records were among those involved in a massive breach of personnel records held by the Office of Personnel Management that some US officials have blamed on China. China denies any involvement in hacking US databases.

James said the air force took a hard look at its cyber security immediately after the revelations and decided to redouble its efforts, although no new actions were needed.

She said the service was cataloging weapons and IT systems to detect any possible vulnerabilities, while also working to set up 39 cyber security teams around the country.