The Russian military may surpass U.S. military capability in Europe by 2025, Gen. Curtis M. Scaparrotti, head of U.S. European Command, told lawmakers on Thursday. He emphasized that keeping up EUCOM’s modernization was key to keeping up and maintaining superiority.

“Given their modernization, the pace that it’s on … we have to maintain our modernization that we’ve set out so that we can remain dominant in the areas that we are dominant today,” said Scaparrotti. “If we were not to do that, I think that their pace would put us certainly challenged in a military domain in almost every perspective by, say, 2025.”

Last month, EUCOM requested $6.5 billion for its key program in the region, the European Deterrence Initiative, which bolsters air, sea, and land forces across the continent. That’s $2 billion more than requested in fiscal 2018. EUCOM leaders said it reflected the need to “deter aggression and malign influence in Europe by increasing our air, sea and land force responsiveness, and expanding interoperability with multi-national forces.”

Russian President Vladimir Putin has been eager to show off of new and eye-catching capabilities in hypersonic weapons. Analysts have also noted a decade of Russian prowess in electronic and cyber warfare, as displayed from Eastern Ukraine to Syria.

Scaparrotti’s warning comes on the heels of a new report from RAND, which notes a growing “imbalance” of U.S. and European forces in Eastern Europe. “Improvements in Russia’s military forces over the last decade have reduced the once-gaping qualitative and technological gaps between Russia and NATO. These improvements come while Russia is expanding its forces in the West, maintaining more high-readiness forces, and gaining valuable combat experience in Ukraine and Syria,” the unclassified version of the report says.

Scaparrotti said his key funding needs include software and hardware for command and control and more sensors and analysis aids for better intelligence surveillance and reconnaissance. He also said EUCOM’s deterrence depends on precision munitions and integrated air and missile defense, particularly in the short and mid-range.

The United States and other NATO and European allies have been working to incorporate realistic Russian cyber attack scenarios into their exercises, he said. “We’ve actually conducted exercises—one this past year—that involved attacks on infrastructure, etc., in order to get…better clarity” on what such attacks might entail and how they might be part of a broader Russian military operation. The next big NATO cyber exercise, Locked Shields, will take place in Tallinn, Estonia, in April and pit NATO forces against one another.

Scaparrotti also said Russia was doubling down on efforts to control Arctic sea lanes. “They would have the capability in some time, perhaps two or three years, to control the Northern Sea route if they chose to do so,” he said, adding “we’re not keeping pace.”

The head of EUCOM also took several questions on Moscow’s propaganda and social-media efforts to destabilize other governments, though this is not technically part of his portfolio as head of U.S. armed forces in Europe. He highlighted Serbia as a key spot where Russia is upping its game and increasing activity.

As for Russia destabilization efforts in the United States, Scaparrotti echoed the sentiments of other commanders, saying that military might alone is not deterring such efforts. He said a broader governmental response, involving diplomatic and economic pressure, would likely have a greater effect.

The Trump Administration has refused to implement Obama-era sanctions against the Kremlin for its illegal election-influencing campaign in 2016. Without getting too political, or mentioning Trump by name, Scaparrotti responded to a question about that sanctions policy with an uniequivocal endorsement for more, non-military pressure on the Kremlin. “Fundamental to deterrence is either denial or an imposition of costs. An effective deterrent has to have one of these,” he said.

See Also: By Lifting Sanctions, Trump Could Hand Russia’s Military a Lethal Technological Advantage