 -- President Obama announced that the U.S. and China have reached a "common understanding" to not conduct or support cyber espionage and intellectual property theft for commercial gain.

"I raised, once again, our rising concerns about growing cyber threats to American companies and American citizens. I indicated that it has to stop," Obama said in a Rose Garden press conference with Chinese President Xi Jinping. "The United States government does not engage in cyber economic espionage for commercial gain."

"We have agreed that neither the U.S. or the Chinese government will conduct or knowingly support cyber-enabled theft of intellectual property, including trade secrets or other confidential business information for commercial advantage," the president added. "We’ll work together and with other nations to promote other rules of the road."

Acknowledging that the U.S. and China are two "major cyber countries," President Xi said "confrontation and friction are not the right choice for both sides."

The agreement marks a major development in U.S.-China relations.Tensions between the U.S. and China have risen over cyber security concerns as both the U.S. government and businesses have faced several damaging hacking attacks over the past year.

"The question now is - are words followed by actions?" President Obama said. "We will be watching carefully to make an assessment as to whether progress has been made in this area."

President Obama said the U.S. is willing to use sanctions and "whatever other tools we have in our tool kit to go after cyber criminals, either retrospectively or prospectively."

THE SOUTH CHINA SEA CONFLICT

The two presidents also discussed China's island building in the disputed territories in the South China Sea, a key trade route for U.S. ships.

"We have the right to uphold our own territorial sovereignty and lawful and legitimate maritime rights and interests," President Xi said. "We are committed to maintaining peace and stability in the South China Sea, managing differences and disputes through dialogue and addressing disputes through negotiation, consultation, and peaceful manner and exploring ways to achieve mutual benefit through cooperation. We're committed to respecting and upholding the freedom of navigation and overflight that countries enjoy according to international law."

"Relevant construction activity that China are undertaking in the islands of South -- Nansha Islands, do not target or impact any country and China does not intend to pursue militarization," he added.

The U.S. has been critical as China has built islands, paved runways and stationed ships in the waters of the South China Sea.

"I reiterated the right of all countries to freedom of navigation and overflight and to unimpeded commerce. As such, I indicated that the United States will continue to sail, fly and operate anywhere that international law allows," President Obama said. "I conveyed to President Xi our significant concerns over land reclamation, construction and the militarization of disputed areas, which makes it harder for countries in the region to resolve disagreements peacefully and I encouraged a resolution between claimants in these areas."

"We are not a claimant. We just want to make sure that the rules of the road are upheld. I reiterated my strong commitment as well to our One China Policy based on the three joint communiques and the Taiwan Relations Act.