China is building military capabilities in the South China Sea that are escalating the tense standoff in the region, the head of U.S. Pacific Command told lawmakers Tuesday.

"In my opinion China is clearly militarizing the South China Sea," said PACOM head Adm. Harry Harris, in a Tuesday hearing before the Senate Armed Services Committee. "You'd have to believe in a flat earth to believe otherwise."

The harsh assessment from the military's top commander in the Pacific comes on the heals of a wave of reports of increasing Chinese capabilities on disputed islands. Last week, satellite images showed China had installed a surface-to-air missile battery on the Paracel Islands near Vietnam. And on Monday, reports surfaced that China is installing a high-tech air search radar that may be capable of detecting U.S. stealth aircraft on one of its man-made islands in the Spratly Islands.

Harris said he needed the U.S. Navy to invest in next-generation anti-surface missiles to counter potential rivals like China who are rapidly building their capabilities , saying the Navy was still using the same weapons it has had since he was a junior officer.

"When I started flying P-3s in the 1970s we had the Harpoon missile, and it's the same one we have today," Harris said.

Admiral Harry B. Harris, Jr., speaks during Senate Armed Service Committee nomination hearings for his reappointment to the grade of Admiral and to be Commander, United States Pacific Fleet at the US Capitol, Tuesday, December 2, 2014.

Admiral Harry Harris, the head of U.S. Pacific Command, says that the U.S. Navy needs to provide more attack subs to his region and to develop new anti-ship missiles to counter potential rivals like China.

Photo Credit: Navy Times staff

× Fear of missing out? Sign up for the Navy Times Daily News Roundup to receive the top Navy stories every afternoon. Thanks for signing up. By giving us your email, you are opting in to the Navy Times Daily News Roundup.

The modified anti-surface version of the SM-6, announced earlier this year, is a step in the right direction, as is the development of the aircraft-launched Long Range Anti-Surface Missile, Harris said.

"The LRASM: it's a great capability that we need to bring on fast," Harris said.