Chinese leader Xi Jinping and Russian President Vladimir Putin hailed their strategic ties and growing energy trade as they met in Beijing Wednesday only days after a visit by U.S. President Donald Trump to China.

Putin and Xi oversaw the signing of more than 40 cooperation agreements in areas such as trade, technology and media exchanges. They stressed their growing trade, particularly in oil and natural gas, and declared themselves aligned on international relations.

The countries’ ties have reached “the highest level in history,” Xi said after the signing ceremony, speaking to members of the delegations and journalists. The two sides also agreed to extend a friendship treaty first signed in 2001.

Putin told those in the room that “the driving force behind economic cooperation is Russian-Chinese collaboration in the energy sector.”

“Amid the crisis in the Middle East, Russia continues to maintain its role as a reliable supplier of resources, while China remains a responsible consumer of these resources,” Putin added, an apparent reference to the U.S. war in Iran.