Donald Trump announced a “very substantial phase one deal” to solve the long-running trade dispute with China.

After a two-day meeting in Washington between US and Chinese officials on Friday Trump announced a delay on plans to raise tariffs on $250bn worth of goods to 30% on 15 October.

A further 15% tariff on almost all remaining Chinese imports including laptops, smartphone, footwear and clothing is still set to be imposed on 15 December unless a deal can be reached with Beijing.

Trump said progress had been made on allegations of currency manipulation, intellectual property theft and other issues. China also agreed to increase its purchases of US agricultural goods and further open up its market to foreign financial services companies. The deal has not been written yet and may take weeks to finalize.

Speaking in the White House Trump said: “I think we have a lot of good faith right now.” He said the agreement was bigger than a trade deal. “There was a lot of friction between the US and China and now it’s a lovefest,” said Trump.

Earlier Trump had tweeted there were “warmer feelings” in US-China trade talks. The news helped boost stock prices with the Dow Jones Industrial Average closing up 319 points and the S&P 500 snapping a three-week losing streak.

“Good things are happening at China Trade Talk Meeting. Warmer feelings than in recent past, more like the Old Days,” Trump said on Twitter shortly after officials resumed negotiations for a second day.

“All would like to see something significant happen!”

This week’s talks are the 13th round of discussions aimed at ending a 15-month trade battle between the world’s two largest economies that has rattled stock markets worldwide.

The breakthrough came as negotiations had appeared headed for yet another crisis after Washington barred Chinese tech companies from the US in the wake of Beijing’s persecution of Muslim minorities.

Tensions were further exacerbated by a row over a tweet from Daryl Morey, the general manager of the Houston Rockets basketball team, in support of the Hong Kong democracy movement.

US tariffs on hundreds of billions of dollars in Chinese merchandise were due to rise on Tuesday.

Even a partial win would be a boon for Trump, who faces an impeachment firestorm and stinging criticism in Congress for his treatment of Kurdish allies in Syria, only the latest episodes of the White House’s perpetual turmoil.

But breakthroughs on trade talks have come and gone before. Since the China trade war began last year, moments of comity and cheer have more than once been shattered, giving way to jolting deteriorations in relations between the two sides.

In the spring, officials said a deal was more or less at hand, only to have Washington resume tariff increases in May, accusing Beijing of reneging on core commitments already put down in writing.

The US Treasury in August branded China a currency manipulator, accusing Beijing of deliberately weakening its currency to gain unfair trade advantages. The move made good on a Trump campaign pledge to crack down on China, a country he accused of “raping” the US economy.

In Beijing, the foreign ministry spokesman, Geng Shuang, also told reporters on Friday that China hoped “to promote positive progress” in the talks.

Media reports this week have drawn the contours of a partial deal that, while not addressing Trump’s biggest gripes about China’s trade practices, would offer something for both sides.

China will continue to increase purchases of US farm exports and pledge to refrain from currency manipulation while Washington will suspend a tariff increase, Bloomberg reported.

China has so far balked at Trump’s demands for profound changes in the way Beijing manages its economy, which analysts say could politically undermine the Communist party.

In an editorial on Friday, the party-owned China Daily said a partial deal “is a more feasible objective and one that would be in the common interests of both sides”.

Meanwhile, the Trump administration has continued to examine ways in which it could exert more pressure on Beijing beyond simply taxing Chinese imports.

Washington accuses China of attempting to dominate global industry through massive state intervention in markets, theft of intellectual property, hacking and subsidies, accusations shared by Europe and Japan.

Larry Kudlow, a top White House economic aide, said this week this could include heightened regulatory scrutiny of Chinese companies operating in the United States.

The president added in a later tweet he would also be able to skip the process of congressional approval: “When the deal is fully negotiated, I sign it myself on behalf of our Country. Fast and Clean!”

Congress has yet to ratify a revamped North American trade pact which Trump signed last year.