(Bloomberg) -- China and Iran signed an overarching deal aimed at charting the course of their economic, political and trade relations over the next 25 years, Iranian state TV reported, in a challenge to the Biden administration.

The “Comprehensive Strategic Partnership” agreement, signed in Tehran on Saturday by Iranian Foreign Minister Mohammad Javad Zarif and his Chinese counterpart, Wang Yi, has been in the works since 2016, when President Xi Jinping became the first Chinese leader to visit the Iranian capital in over a decade.

“The document can elevate bilateral ties to a new strategic level,” Foreign Ministry Spokesman Saeed Khatibzadeh said in a televised interview. The deal focuses on boosting private-sector collaboration and the Islamic Republic’s role in Xi’s flagship infrastructure and investment program, the Belt and Road Initiative, he said.

A draft copy of the outlines of the accord that surfaced on media last year showed plans for long-term supply of Iranian crude to China as well as investment in oil, gas, petrochemical, renewables and nuclear energy infrastructure.

The alliance between Beijing and Tehran is a challenge to U.S. President Joe Biden’s administration as it sets about trying to rally allies against China, which Secretary of State Antony Blinken has said is the world’s “greatest geopolitical test.”

The China pact comes as efforts to revive the Iran nuclear accord with world powers are stalled. The Biden administration has indicated that it is open to reengaging with Iran after then-President Donald Trump abandoned the deal nearly three years ago and reimposed economic sanctions, but the two sides have yet to even agree to meet.

Iran’s closer integration with China may help shore up its economy against the impact of the U.S. penalties, while sending a clear signal to the Biden administration of Tehran’s intentions. Wang Yi, who arrived in Tehran on Friday, also met with President Hassan Rouhani to discuss the nuclear deal.

In a televised speech, Rouhani reiterated his view on the prospect for the easing of restrictions before the end of his second and final term as president in early August.

“We’re ready for the lifting of sanctions,” he said on Saturday. “If obstacles are removed, all or at least some sanctions can be lifted.”

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