Biden and Xi met for about four hours on the outskirts of San Francisco on Wednesday and covered pressure points that have contributed to strained US-Chinese relations.
Beijing said the leaders agreed to resume military contacts China severed after then-House of Representatives Speaker Nancy Pelosi visited Taiwan in 2022.
Biden requested both countries institutionalise the dialogues and Secretary of Defense Lloyd Austin will meet his Chinese counterpart when that person is named, a senior US official said.
US and China's militaries have had a number of near-misses and acrimonious exchanges over the past year.
Biden and Xi agreed to co-perate on addressing the source of the opioid fentanyl, a leading cause of drug overdoses in the United States.
Under the agreement, China will go directly after specific chemical companies that make fentanyl precursors, a senior US official told reporters.
Xi sought to reassure Biden about Chinese intentions toward democratic Taiwan, which China claims as its territory, saying China has no plans for military action against Taiwan in coming years.
President Biden and President Xi spoke for about four hours.
Yet he did lay out conditions where the use of force could be used, the US official said. Biden asked China to respect Taiwan's electoral process.
Biden welcomed the Chinese leader at Filoli estate, a country house and gardens about 48 km south of San Francisco, where they will move later for a summit of the Asia-Pacific Economic Cooperation forum.
Biden said the US and China had to ensure competition between them "does not veer into conflict" and manage their relationship responsibly.
He said issues such as climate change, counter-narcotics and AI demanded joint attention.
After a morning session of talks and before heading into lunch with Xi, Biden said on social media platform X it was vital they understood each other "leader to leader".
"There are critical global challenges that demand our joint leadership. And today, we made real progress," he said, without elaborating.
After lunch, the leaders took a short walk in the manicured garden of the mansion following an interaction that lasted around four hours.
Biden gave two thumbs up when asked how the talks were going.
"Well," he said.
President Biden and President Xi took an after lunch walk.
A White House statement said the leaders "held a candid and constructive discussion on a range of bilateral and global issues and exchanged views on areas of difference."
Xi told Biden as they began their talks a lot had happened since their last meeting a year ago in Bali.
"The world has emerged from the COVID pandemic but is still under its tremendous impacts. The global economy is recovering but its momentum remains sluggish."
He called the US-China relationship "the most important bilateral relationship in the world" and said he and Biden "shoulder heavy responsibilities".
"For two large countries like China and the United States, turning their back on each other is not an option," he said.
"It is unrealistic for one side to remodel the other and conflict and confrontation has unbearable consequences for both sides."
The leaders will be seeking to reduce friction but deep progress on the vast differences separating them may have to wait for another day.
