Australia is expected to buy up to five U.S. Virginia class nuclear powered submarines in the 2030s as part of a landmark defense agreement between Washington, Canberra and London, four U.S. officials said on Wednesday, in a deal that would present a new challenge to China.

The agreement, known as the AUKUS pact, will have multiple stages with at least one U.S. submarine visiting Australian ports in the coming years and end in the late 2030s with a new class of submarines being built with British designs and American technology, one of the officials said.

U.S. President Joe Biden will host leaders of Australia and Britain in San Diego on Monday to chart a way forward for provision of the nuclear-powered submarines and other high-tech weaponry to Australia.