U.S. President Joe Biden will seek to engage with Chinese President Xi Jinping in the coming months, White House National Security Adviser Jake Sullivan said Thursday, suggesting the possibility of a bilateral meeting on the sidelines of the Group of 20 summit to be held in Italy later this year.

"We don't have any particular plans at the moment. But I would note that both leaders are likely to be at the G-20 in Italy in October," he said during a conference call about Biden's just-ended week in Europe.

Sullivan said the United States will "soon enough" start working out the "right modality" for the two presidents to engage, which could be a phone call, a meeting on the margins of an international summit, or something else.

He also said the engagement is intended to "take stock of where we are in the relationship" and to ensure that there is "a kind of direct communication" between Biden and Xi.

During his trip to Europe, Biden held talks with the leaders of the Group of Seven industrialized nations, the North Atlantic Treaty Organization and the European Union as he rallies democracies to counter what he views as autocracies such as Russia and China.

On the final leg of his trip, the U.S. president met Russian President Vladimir Putin in Geneva, the first meeting between the two since Biden took office in January. Attention is now shifting to the possibility of a face-to-face meeting with Xi.

The Biden administration has said that dealing with China will be "the biggest geopolitical test" of this century, singling out the rising Asian nation as having the power to pose serious challenges to the open international system the United States is defending.