(CNN) After meeting for dinner in December 2018 on the sidelines of a major international summit in Argentina, President Donald Trump and Chinese leader Xi Jinping raised the prospect of an imminent deal to end their tit-for-tat trade war.

Here's a timeline of key events in the talks since then:

Trump and Xi, joined by top aides, agree to a temporary truce on tariffs and what the White House says is a 90-day round of negotiations toward a comprehensive deal.

With Beijing declining to confirm the 90-day clock, Trump tweets that, while he remains optimistic about talks, he is still prepared to raise tariffs if no deal is reached: "I am a Tariff Man." Markets tank.

Chinese officials and Trump move to reassure investors by sending positive signals about the talks.

January 7, 2019: US negotiators head to Beijing for a US negotiators head to Beijing for a first round of face-to-face talks despite the partial shutdown of the federal government back in Washington.

January 30-31, 2019: China's top negotiator, Vice Premier Liu He, visits Washington for further talks. Trump sends China's top negotiator, Vice Premier Liu He, visits Washington for further talks. Trump sends mixed messages , saying talks are progressing "well" but that a final deal would only be made directly between Xi and him.

February 15, 2019: Another round of talks in Beijing closes with Xi meeting briefly with US negotiators, including Treasury Secretary Steven Mnuchin, who calls the meetings "productive" in a tweet. Later, White House press secretary Sarah Sanders says in a statement Another round of talks in Beijing closes with Xi meeting briefly with US negotiators, including Treasury Secretary Steven Mnuchin, who calls the meetings "productive" in a tweet. Later, White House press secretary Sarah Sanders says in a statement "much work remains."

March 20, 2019: Trump signals that he intends to Trump signals that he intends to leave existing tariffs in place even if a deal is signed , in order to retain leverage over Beijing.

May 5, 2019: Ahead of a planned visit by Chinese negotiators to Washington, Trump reactivates his threat to Ahead of a planned visit by Chinese negotiators to Washington, Trump reactivates his threat to escalate tariffs as originally promised before trade talks kicked off in December.

May 6, 2019: Lighthizer and Mnuchin Lighthizer and Mnuchin confirm plans the US will move forward with the President's threat to escalate tariffs on $200 billion of Chinese goods set to go effect on May 10, after claiming Beijing officials had reneged on prior commitments.

May 8, 2019: China China threatens to retaliate , but moves ahead with sending a delegation to Washington.

May 9-10: Lighthizer, Mnuchin and Liu hold talks and a working dinner.

May 10, 2019: US raises tariffs from US raises tariffs from 10% to 25% on $200 billion in Chinese goods after the talks end without an agreement . US officials formally open the door to adding new tariffs to another $300 billion in goods -- "essentially all remaining imports from China," including consumer items like toys and electronics left out of the initial tariff round.

May 13, 2019: Beijing strikes back, hiking tariffs to 25% Beijing strikes back, hiking tariffs to 25% on $60 billion in US exports , including cotton, machinery, grains and aircraft parts.

June 28, 2019: Trump meets with Xi. At a news conference the next day, Trump says he promised not to raise tariffs further, and Trump meets with Xi. At a news conference the next day, Trump says he promised not to raise tariffs further, and said negotiators would pick up "where we left off" before the tariff escalation in May.

July 30, 2019: Mnuchin and Lighthizer Mnuchin and Lighthizer wrap up discussions in Shanghai and agree to continue talks in early September.

August 1, 2019: Trump announces in a tweet that he will impose a Trump announces in a tweet that he will impose a 10% tariff on $300 billion in remaining Chinese imports starting September 1.

August 13, 2019: After Lighthizer, Mnuchin and Liu agree in a call to restart negotiations in September, After Lighthizer, Mnuchin and Liu agree in a call to restart negotiations in September, Trump agrees to delay imposing new tariffs on some consumer goods until December 15 -- a move that also relieves concerns about depressing consumer spending heading into the holiday season.

August 23, 2019: Beijing unveils a Beijing unveils a new round of tariffs of up to 10% on $75 billion in US goods -- including whiskey -- and announces plans to reimpose tariffs on US autos and parts starting December 15. Trump responds with a threat to raise tariffs to 30% from 25% on Chinese goods already being taxed , and to bump up his planned tariff on consumer goods from 10% to 15%.

August 26, 2019: Trump indicates a resumption of talks, claiming in a news conference at the G7 summit in France that Trump indicates a resumption of talks, claiming in a news conference at the G7 summit in France that Mnuchin had "many calls" concerning China . China's Foreign Ministry declines to confirm any such calls, and Mnuchin describes "communications" rather than calls.

September 1, 2019: from both sides, hitting Chinese-made consumer goods coming into the US and some US products entering China. Fresh tariffs go into effect from both sides, hitting Chinese-made consumer goods coming into the US and some US products entering China.

September 5, 2019: The US and China agree to The US and China agree to resume talks in early October after a phone call among Liu, Lighthizer and Mnuchin.

September 11, 2019: Beijing Beijing exempts some US goods -- including shrimp and cancer drugs -- from tariffs, and Trump pushes back his threatened tariff hike on Chinese goods already being taxed from October 1 to October 15.

September 13, 2019: Beijing adds Beijing adds US soybeans and pork to its exempted list.

October 11, 2019: In an Oval Office appearance alongside Liu, Trump announces a In an Oval Office appearance alongside Liu, Trump announces a "very substantial phase one deal" -- then says it will take three to five weeks to get it finalized on paper and suggests he will meet Xi at the Asia-Pacific Economic Cooperation Summit scheduled for mid-November in Chile. He says he will cancel a planned tariff increase to 30% for some goods.

October 30, 2019: Chile Chile cancels APEC summit amid violent protests. There's no backup site.

November 8, 2019: Trump throws cold water on comments from China's Foreign Ministry about tariff rollbacks, telling reporters: Trump throws cold water on comments from China's Foreign Ministry about tariff rollbacks, telling reporters: "I haven't agreed to anything."

November 22, 2019: Xi says in Beijing that he hopes to work out an agreement based on Xi says in Beijing that he hopes to work out an agreement based on "mutual respect and equality." Trump says in a "Fox & Friends" interview that the US and China have a deal "potentially very close."

December 3, 2019: Speaking on the sidelines of a NATO summit, Trump suggests Speaking on the sidelines of a NATO summit, Trump suggests a deal might not be struck until after the 2020 election : "In some ways, I think it's better to wait 'til after the election, you want to know the truth."

December 12, 2019: US and Chinese negotiators reach tentative US and Chinese negotiators reach tentative phase one trade deal

This story has been updated with events.