President Joe Biden finally got his frank, face-to-face discussion with China’s Xi Jinping.

His next challenge is to steer the U.S. away from a military conflict with China over the nations’ sharp ideological differences and find a way to hold Xi accountable for commitments he made during the summit.

Biden said at a news conference after their meeting that he trusts Xi will take promised steps to cut back on the flow and production of fentanyl – a synthetic drug involved in a record-breaking number of overdose deaths in America. And while he said he would seek verification, Biden said he found it reassuring that Xi promised to accept his calls.

“We have disagreements. He has a different view than I have on a lot of things. But he’s been straight,” Biden said of his counterpart.

Of their agreement to keep talking, he said: “That’s an important progress.”

National Security Council Coordinator for Strategic Communications John Kirby told reporters Thursday that Xi told Biden during their meeting that he does not want to see Americans die because of fentanyl and made a personal commitment to minimize exports.

“So, we’re very hopeful that it will have a very practical, significant effect here over time,” Kirby said.

Xi’s promises to have Chinese law enforcement crack down on the shipment of chemicals that cartels in Latin America are using to make the drugs and restore high-level communications between the U.S. and Chinese militaries is being met with cautious optimism from experts and lawmakers.

But they worry the tactical détente will be temporary and could be superficial, as Xi seeks to shore up foreign confidence in his country’s struggling economy.

Colleen Cottle, a former Central Intelligence Agency analyst who serves as deputy director of the Atlantic Council’s Global China Hub, said the summit between Biden and Xi does not signal “a long-term, warming of the situation” and may make him more determined to achieve his country’s military and technological ambitions.

“Deep down, Xi is probably very frustrated that he has to continue to rely on the United States and that he had to go to this meeting,” she said.

Xi’s summit with Biden came hours before he addressed CEOs of American companies at a dinner in San Francisco, where the Asian-Pacific Economic Cooperation conference was taking place. Xi suggested at the dinner that he may send more pandas to the U.S.

He called the bears “envoys of friendship between the Chinese and American peoples” and said new pandas could be sent to California.

“I was told that many American people, especially children, were really reluctant to say goodbye to the pandas and went to the zoo to see them off,” Xi said.

The idea that China would lease the U.S. additional pandas, “that’s being done with a hope that this will unlock some more foreign investment or ease the minds of investors,” Cottle said. 

When it comes to dominating the world’s economy, China cannot be counted on to play by the rules, without any guardrails, Senate Foreign Relations Committee Chairman Ben Cardin, D-Md., said in an interview.

But he said there is a “reasonable chance” that Xi will follow through on his pledges to resume military-to-military communications and slow the flow of fentanyl.

“Xi is very strategic. He has a game plan. And he uses every opportunity to advance his game plan,” Cardin said. “If he believes it’s in his interest and what he’s trying to achieve, he will follow up on those commitments. I think he doesn’t make commitments with the idea of not living up to those commitments.”

The Trump administration also scored a deal on fentanyl with China that was meant to substantially curb overdose deaths and did not have the intended effect. 

Rep. Michael McCaul, the House Foreign Affairs Committee chairman, said he was “very skeptical” about Biden’s fentanyl deal. But he praised the pledge to reestablish communications between China’s generals and U.S. military officials as a “very, very good outcome.”

“I think the military-to-military channels would be helpful, if achievable,” the Republican congressman and frequent Biden critic said.

Beijing has been increasingly aggressive toward Taiwan, where democratic elections are scheduled to take place in January, and U.S. allies in the region such as the Philippines. Just last week, Chinese ships chased and surrounded Philippine vessels in the South China Sea in a move the U.S. condemned as harassment.

Biden emphasized after his meeting with Xi on Wednesday at a secluded estate outside San Francisco that the relationship has not developed into a conflict, yet, and said he was sure that Xi fully understands there would be consequences for a confrontation.

He said he also warned Xi not to interfere in Taiwan’s election.

Chinese state media reported after the meeting that Xi made clear to Biden that “China will realize reunification, and this is unstoppable” and pushed him to quit providing military assistance to Taiwan. Xi also pressed Biden to affirm the U.S. does not support Taiwan breaking off and becoming an independent nation.

Washington and Beijing are not necessarily on a military collision course, said former U.S. Ambassador to China Gary Locke.

“Unstoppable could mean 30 years from now, 20 years from now, 15 years from now, doesn’t necessarily mean it’s going to be done by force,” Locke said.

Locke, who was ambassador to China and U.S. Commerce secretary during the Obama administration, said hard and fast agreements were never expected to come out of the meeting. However, it was necessary for the leaders to have a conversation about the areas of disagreement and “get it out in the open.”

Kirby said Biden made it clear to Xi that the U.S. does not support Taiwanese independence. But the White House spokesman said the U.S. will not stop providing weapons to Taiwan that Taipei could use to defend itself in the event of an attack.

Biden approved sending Taiwan $345 million in weapons over the summer. He asked Congress for $2 billion for security assistance for partners in the Indo-Pacific to deter acts of aggression in an emergency spending request last month. The funding request did not mention Taiwan specifically, but lawmakers say that’s what the money will primarily be used for.

“Any force, military type action would be totally unacceptable,” Cardin said of China’s provocations. “And I think you’re going see Congress take some steps in the next couple of weeks to underscore the importance of Taiwan being protected from such type of potential aggression.”

The U.S. has said that China is gearing up to have the military capability to invade Taiwan by 2027. McCaul said he believes the timeline could be “accelerated,” depending on the outcome of the island’s January election. 

“It could happen within the next year,” McCaul warned.

Beyond democracy and human rights concerns, that would pose a problem for America, he said, because Taiwan produces more than 90% of the world’s advanced microchips.

“We find ourselves in a very dangerous situation,” the Texas congressman said.