The U.S. and China said they made progress in trade talks and agreed to meet again in Beijing as they look for a breakthrough with only a month to go before the Trump administration is set to ratchet up tariffs.

President Donald Trump said Thursday he will dispatch two of his top negotiators to China following two days of talks with Chinese officials in Washington. Treasury Secretary Steven Mnuchin and U.S. Trade Representative Robert Lighthizer will visit the Asian nation in mid-February to hold the next round of talks.

Trump also said he may meet with President Xi Jinping in an effort to end the trade war, possibly after the U.S. president’s planned summit with North Korean leader Kim Jong Un in late February.

The teams have made “tremendous progress” but that “doesn’t mean we have a deal,” Trump told reporters in the Oval Office after meeting with Chinese Vice Premier Liu He. China has agreed to buy a substantial amount of American soybeans, the president added, calling the offer a sign of good faith.

The agreement to continue talking raises hopes the world’s two biggest economies could find a way to end the conflict before March 1, when the U.S. has said it will more than double tariffs on $200 billion of Chinese goods. But there was little concrete evidence they bridged yawning differences over the toughest issues such as China’s policy on intellectual property and the heavy involvement of the state in its economy.

In a statement, the White House didn’t list any new commitments by either side, saying only that progress had been made and “much work remains to be done.” The White House reiterated its threat to raise tariffs by March 1, unless a “satisfactory outcome” is reached.

The slow pace of talks sets up what could be a tense countdown to the deadline, with a personal meeting between Trump and Xi looming as perhaps the only way to end the impasse.

“The statement certainly signals progress, but at best limited progress on the core long-term structural issues that separate the two sides,” said Eswar Prasad, a trade policy professor at Cornell University. “The statement ends with a not-so-veiled threat that China will need to offer more substantive concessions to enable a deal that would take further tariffs off the table.”

Lighthizer led the two days of negotiations in Washington with Liu, the highest-level talks since Trump met Chinese President Xi Jinping on Dec. 1 and declared a 90-day trade truce.

Liu said that China hopes to accelerate that timetable. But it will likely take a meeting of the presidents to break the deadlock, said Derek Scissors, a China expert at the American Enterprise Institute. He said a Trump-Xi summit “is, as it has always been, the main event.”