The top U.S. commander in Europe is warning of daunting amounts of Chinese investment in European seaports and increases in Russian submarine activity outside of Europe, reports Voice of America.

U.S. Air Force Gen. Tod Wolters, commander of U.S. European Command and NATO’s Supreme Allied Commander Europe (SACEUR), testified at a Senate Armed Services Committee hearing Tuesday that “China has access to 10% of the shipping rights into and out of Europe.”

Wolters told lawmakers that China has invested an “economic majority” in seaports across Europe, including in NATO allies Belgium, Italy, France and Greece.

European allies have been surprised and concerned by the degree of equities China holds with respect to seaports, according to the general.

The commander also echoed concerns about the Chinese company Huawei’s 5G wireless technology, which U.S. Secretary of Defense Mark Esper, U.S. Secretary of State Mike Pompeo and NATO Secretary-General Jens Stoltenberg discussed in Munich last week.

Wolters affirmed the use of Huawei’s 5G technology is an intelligence threat to U.S. soldiers in Europe.

In addition to concerns about China, Wolters also sounded the alarm over Russian submarine activity, a threat that prompted the reactivation of the U.S. 2nd Fleet to protect the Northern Atlantic in 2018.

Wolters said that in summer and fall of 2018, and summer and fall of 2019, the U.S. military saw “a 50% increase in the number of resources in the undersea that Russia committed” to submarine patrol operations outside of the European region.