(WASHINGTON):, June 16 (Reuters) - Senior US officials are having discussions about a possible phone call between President Joe Biden and Chinese President Xi Jinping this summer, an administration official said on Thursday (Jun 16).

The disclosure came just days after Biden's national security adviser, Jake Sullivan, held four and a half hours of talks in Luxembourg with China's top diplomat Yang Jiechi about a host of issues.

Biden and Xi last spoke on Mar 18, a conversation dominated by US concerns that China might provide material support for Russia in its invasion of Ukraine.

Since then, concerns are rising that North Korea might be planning a nuclear test.

"There’s a discussion about possible Biden-Xi engagement but we don't have anything planned or confirmed at this time," said an administration official.