The world's top two economies are negotiating a final agreement to resolve their year-long trade war.

US President Donald Trump said Monday that talks on a trade deal with Beijing have resumed following a weekend truce struck with China's Xi Jinping on the sidelines of the Group of 20 summit.

Trump and Xi agreed Saturday to hold off on new tariff increases as the world's top two economies negotiate a final agreement to resolve their year-long trade war.

Trump also offered to relax some restrictions on US technology exports to Chinese telecoms giant Huawei, triggering a backlash from some US lawmakers.

"It's already begun," Trump told reporters at the White House when asked if trade negotiations had restarted.

"They're speaking very much on the phone but they're also meeting."

But he suggested the deal should be "tilted" toward the United States.

"It has to be better for us than for them because they had such a big advantage for so many years," he added, referring to China's soaring US trade surplus, which Trump views as a loss for the United States.

"Obviously, we can't make a 50/50 deal. It has to be a deal that is somewhat tilted to our advantage."

At the weekend, Trump also offered to relax some restrictions on US technology exports to China's telecoms giant Huawei, which American officials describe as a tool of Chinese espionage.

But the Republican leader said any final resolution of the matter would have to come when both sides strike a final bargain.

The apparent thaw in US-China trade relations drew a collective sigh of relief from global markets, which staged a relief rally Monday even though major questions about any deal remain unanswered.

Trump in May jacked up tariffs on more than $200 billion in Chinese imports after accusing Beijing of suddenly reneging on commitments made during extensive negotiations begun last year.

Washington has accused Beijing of massive state intervention in markets as well as the forced transfer and outright theft of American technological know-how.

But analysts say China is unlikely to accede to US demands, which could undermine the Communist Party's hold on power.