President Donald Trump and Chinese President Xi Jinping discussed trade and North Korea in a phone call Tuesday, as Xi’s top economic adviser plans additional talks in Washington following last week’s trip by U.S. officials to Beijing.

The two men discussed Xi’s meeting with North Korean leader Kim Jong Un and agreed on the importance of continuing sanctions on North Korea until it permanently dismantles its nuclear and missile programs, according to a statement from White House Press Secretary Sarah Huckabee Sanders.

Trump also affirmed his commitment to ensuring that the U.S. and China have a balanced investment and trade relationship, the statement said.

The call followed Xi’s meeting with the North Korean leader in the port city of Dalian over the past two days, the second meeting between top officials of the two Communist allies in less than two months. Kim told Xi that North Korea does not need nuclear weapons as long as security threats and hostility against the nation are eliminated, the official Xinhua News Agency reported. Kim had a summit with President Moon Jae-in of South Korea late last month and is expected to meet with Trump, possibly next month.

On Monday in Washington, Trump was briefed by members of the U.S. delegation led by Treasury Secretary Steven Mnuchin, who returned to Washington on the weekend from a two-day visit to China.

Liu He will travel to Washington next week, Sanders said on Monday. Liu was recently promoted to vice premier and is Xi’s top deputy on economic matters.

China’s Ministry of Foreign Affairs, Ministry of Commerce and State Council Information Office didn’t immediately respond to faxed requests for confirmation.

“The president has a great relationship with President Xi and we are working on something we think will be great for everybody,” Sanders said in Washington. “China’s top economic adviser, the vice premier, will be coming here next week to continue the discussions with the president’s economic team. We will keep you posted as the discussions are ongoing.”

Mnuchin’s delegation wrapped up two days of talks with Chinese economic officials on Friday with only an agreement to keep talking. Trump has threatened to impose tariffs on as much as $150 billion in Chinese goods, duties that can be imposed after a public comment period ends May 22.

Mnuchin will be part of a U.S. delegation to Jerusalem on May 14 to open the new American embassy to Israel, but will return in time to meet with Liu, a Treasury spokesman said.

The two sides appear to be at loggerheads, with both making long lists of demands the other won’t meet, analysts say. Trump wants China to cut its annual trade surplus with the U.S. by at least $200 billion by the end of 2020 and refrain from retaliation against proposed U.S. tariffs. China wants the U.S. to stop an investigation into the country’s acquisition of sensitive American technologies.

“The U.S. has demanded too much. The upcoming visit is unlikely to yield a deal, but may make some progress,” said Wang Yong, a professor at the School of International Studies at Peking University. “Both sides have pressure as the implementation date of tariffs related to the 301 investigation draws near.”

Liu told American business leaders while visiting Washington earlier this year that he’d take steps to reform China’s economy, according to a person familiar with the situation. Liu said at the time that he had three requests for the Trump administration: Establish a new economic dialogue, name a point person on China issues and hand over a specific list of demands, the person said.

“Last Thursday-Friday’s talk was too demanding and China probably won’t accept all the lists as given, but there are a lot of places where both countries can talk more, for example in terms of market access, IP protection, trade practices and more importantly Made in China 2025,” Liu Li-gang, chief China economist at Citigroup Inc., said in a Bloomberg Television interview from Hong Kong. “In all these areas there’s wiggle room for both sides to have some constructive talks.”