WASHINGTON (AP) — President Joe Biden and China’s Xi Jinping held the fifth conversation of their presidencies on Thursday, speaking for more than two hours as they chart the future of their complicated relationship at a time of simmering economic and geopolitical tensions.

The call began at 8:33 a.m. EDT and ended at 10:50 a.m. EDT, according to the White House. It took place as Biden aims to find new ways to work with the rising global power as well as strategies to contain China’s influence around the world. Differing perspectives on global health, economic policy and human rights have long tested the relationship — with China’s refusal to condemn Russia’s invasion of Ukraine adding further strain.

“The two heads of state had in-depth communication and exchanges on China-U.S. relations and issues of mutual concern,” China Central Television reported on its website.

The latest pressure point has been House Speaker Nancy Pelosi’s potential visit to Taiwan, the island that governs itself democratically and receives informal defensive support from the U.S., but which China considers part of its territory. Beijing has said it would view such a trip as a provocation, a threat U.S. officials are taking with heightened seriousness in light of Russia’s incursion into Ukraine.

“If the U.S. insists on going its own way and challenging China’s bottom line, it will surely be met with forceful responses,” Zhao Lijian, a spokesperson for China’s Foreign Ministry, told reporters earlier this week. “All ensuing consequences shall be borne by the U.S.”

Pelosi would be the highest-ranking U.S. elected official to travel to Taiwan since Republican Newt Gingrich visited the island in 1997 when he was House speaker. Biden last week told reporters that U.S. military officials believed it was “not a good idea” for the speaker to visit the island at the moment.

John Kirby, a U.S. national security spokesman, said Wednesday that it was important for Biden and Xi to regularly touch base.

“The president wants to make sure that the lines of communication with President Xi remain open because they need to,” Kirby told reporters at a White House briefing. “There are issues where we can cooperate with China on, and there are issues where obviously there are friction and tension.”

Biden and Xi last spoke in March, shortly after the Russian invasion of Ukraine.

“This is one of the most consequential bilateral relationships in the world today, with ramifications well beyond both individual countries,” Kirby said.

The conversation comes as Biden has moved to shift U.S. reliance off Chinese manufacturing, including Senate passage Wednesday of legislation to encourage semiconductor companies to build more high-tech plants in the U.S. Biden wants to marshal global democracies to support infrastructure investments in low- and middle-income nations as an alternative to China’s “Belt and Road Initiative,” which aims to boost China trade with other global markets.

Kirby listed a number of areas of U.S,-China friction that he said would be part of the conversation, including “tensions over Taiwan, tensions over … China’s aggressive course of behavior in the Indo-Pacific outside of Taiwan, tensions in the economic relationship” and over China’s reaction to Russia’s war in Ukraine.

Biden, who has kept in place Trump-era tariffs on many Chinese-manufactured goods in order to maintain leverage over Beijing, is weighing whether to ease at least some of them in a move to lessen the impact of soaring inflation on American households.

U.S. officials have also criticized China’s “zero-COVID” policy of mass testing and lockdowns in an effort to contain the spread of COVID-19 in its territory, labeling it misguided and fretting that it will further slow global economic growth.

Other points of strain include China’s treatment of Uyghur Muslims, which the U.S. has declared a genocide, its militarization in the South China Sea, and global campaign of economic and political espionage.