CANBERRA, March 14 (Reuters) - Australia offered China a briefing over its nuclear-powered submarine deal with the United States and Britain but is not aware of any response from Beijing, Defence Minister Richard Marles said on Tuesday.

The government has made more than 60 calls over the last week to leaders including in the Pacific and southeast Asia to inform them about the agreement, known as the AUKUS pact, Marles said during a televised media briefing.

U.S. President Joe Biden, Australian Prime Minister Anthony Albanese and British Prime Minister Rishi Sunak on Tuesday unveiled details of a plan to provide Australia with nuclear-powered attack submarines, a major step to counter China's ambitions in the Indo-Pacific.

China "firmly objects" to the nuclear submarine agreement, its foreign ministry said this month.