U.S. Secretary of State Antony Blinken said on Wednesday that China was acting aggressively and repressively, citing its actions in the East and South China Seas where it has territorial disputes with Japan and other Asian nations.

Speaking to a roundtable of Japanese journalists in Tokyo, Blinken said Beijing was "raising tensions not diminishing them" in the region by its maritime actions and posturing over Taiwan.

Blinken is visiting Japan and South Korea along with Defense Secretary Lloyd Austin in a bid to fortify Washington's alliances in Asia, in a first overseas trip by top-level members of President Joe Biden's administration.

China's extensive territorial claims in the East and South China Seas have become a priority issue in an increasingly testy Sino-U.S. relationship and are an important security concern for Japan.

Blinken said Beijing was "acting both more repressively at home and more aggressively abroad, including in the East China Sea, including with regard to the Senkakus, as well the South China sea and also with regard to Taiwan".

The Senkakus, also referred to as Diaoyu in China, are islets in the East China Sea controlled by Japan but claimed by China.

"Japan has real interest in what happens with regard to Taiwan and Taiwan's straits and we spent some time comparing notes on that," said Blinken describing his Tuesday talks with Japanese officials.

The comments echoed statements issued by Blinken, Austin and their Japanese counterparts after "2+2" talks held in Tokyo on Tuesday and come ahead of Blinken's first in-person meetings with Chinese counterparts planned for later this week in Alaska.

"We look forward to the opportunity to lay out in very clear terms to our Chinese counterparts some of the concerns that we have about the actions they're taking," said Blinken.

Following the morning roundtable with emerging Japanese reporters Blinken and Austin were set to leave for Seoul to hold "2+2" talks with South Korean counterparts until Thursday.