St. PETERSBURG, Russia — Russia has welcomed the Chinese telecommunications company Huawei to develop part of its next-generation wireless technology, even as the United States is trying to convince allies that the company poses a prohibitive security risk.

Russia said Huawei would help build its new high-speed wireless network, known as 5G, in a deal signed on Thursday, the first day of a three-day visit by President Xi Jinping of China. The United States’ dispute over Huawei suggests that the world will be divided, with some countries accepting the Chinese maker’s equipment and others not. The 5G technology will usher in a major leap for all kinds of devices, especially those that are part of the so-called internet of things.

American authorities say that relying on Huawei equipment would open a window to possible Chinese surveillance of everyday life, with technical breaches possible. Despite a history of vigilance about foreign spying with multiple laws intended to protect data, the Kremlin highlighted the agreement between Huawei and MTS, one of the three largest cellphone operators in Russia.

The Kremlin noted that several business deals had been signed in a ceremony attended by President Vladimir V. Putin and Mr. Xi.