He made the remarks during his meeting with US President Barack Obama on the sidelines of the Nuclear Security Summit in Washington on Thursday.
Xi said that China stands for peace and stability in the South China Sea and that all disputes on the matter should be resolved by peaceful means through negotiations.
"China respects and protects the freedom of air and maritime navigation of all countries, based on international law. At the same time, Beijing will not accept any action that damages China's state sovereignty and national interests under the pretext of freedom of navigation," he pointed out.
Xi also expressed hope that the United States will abide by its commitment not to take sides in the South China Sea dispute and will play a constructive role in ensuring peace and stability in the region.
Countries located in the South China Sea area, including Brunei, the Philippines, Malaysia and Vietnam, have expressed competing claims to the disputed Spratly Islands.
The United States has conducted two "freedom of navigation" operations in the South China Sea since October 2015. Last month, the Philippines agreed to give US forces access to several military bases, some of which are close to the disputed territories.
