Iran and the Chinese Communist Party (CCP) have signed a 25-year cooperation agreement despite the fact that both countries are still subject to U.S. sanctions.

Iran’s Foreign Minister Mohammad Javad Zarif and the CCP’s Foreign Minister Wang Yi signed the agreement in Tehran on Saturday, March 27.

Wang met with President Hassan Rouhani and Ali Larijani, a delegate of Supreme Leader Ali Hosseini Khamenei who is said to have been the point person on the 25-year accord, when he arrived in Tehran on Friday for a two-day visit as part of his Middle East journey, according to Al Jazeera.

The agreement’s specifics have yet to be made public, but it is expected to be a broad “strategic accord” that includes substantial CCP investments in Iran’s main sectors including energy and infrastructure, as well as military cooperation.

A draft of the agreement circulated last year included Chinese investments in projects ranging from nuclear energy to ports, railroads, and other infrastructure, as well as military technology transfer and investment in Iran’s oil and gas industry.

According to Iran’s Tasnim news agency, the CCP will receive consistent supplies of Iranian oil in exchange for investments, and the two countries have also agreed to create an Iranian-Chinese bank. A bank like this could aid Tehran in evading U.S. sanctions, which have effectively barred it from global banking systems.

It comes as the United States imposes various levels of sanctions on both Iran and the CCP.

Following his unilateral withdrawal from Iran’s 2015 nuclear agreement with world powers, including the CCP, former U.S. President Donald Trump placed stringent sanctions on Iran, blacklisting the country’s entire financial sector.

Though expressing a willingness to restore the agreement, President Joe Biden has so far declined to lift any sanctions, arguing that Iran must first act to fulfill obligations it reduced in response to U.S. sanctions.

The CCP and Russia have urged the United States to restore the deal by lifting sanctions, although traders and analysts say that amid U.S. warnings, Iran’s oil exports to China increased significantly in March.

On Saturday, Rouhani thanked Wang for the CCP’s position on the nuclear deal and for standing up to “American unilateralism.”

“The two countries’ collaboration to implement the JCPOA, as well as European countries’ implementing commitments, is very necessary and can change the current situation,” he said, referring to the nuclear deal’s formal name.

Wang’s words are quoted by the president’s website: “The new US administration wants to rethink its policy and return to the JCPOA. China welcomes that.”

However, the cooperation agreement has been a source of contention within Iran, where a debate over its goals and merits has split citizens and officials alike.

Proponents of the agreement claim that Iran will benefit from turning east as the United States and the West become more aggressive, while opponents argue that Iran is giving up too much in its quest to strengthen relations with the CCP.