National newspapers are reporting China's reaction to Japan's bid to "nationalise" the disputed Senkaku islands, which are known as the Diaoyu Islands in China.
Japanese Prime Minister Yoshihiko Noda told reporters over the weekend that his government is negotiating to buy the islands in the East China Sea, in response to a similar plan initiated by Tokyo's governor Shintaro Ishihara in April.
"China's holy territory is not 'up for sale' to anyone," said Beijing's Foreign Ministry spokesman Liu Weimin, in remarks quoted by China Daily and others.
The Chinese edition of the Global Times says both Beijing and Taipei - which claims the islands in parallel - "fought back in anger" over Mr Noda's comments.
Taiwan "will not give in for a single inch" in terms of sovereignty, said Taiwan's President Ma Ying-jeou, according to the Global Times' report.
China Daily's editorial says Mr Noda had sent a "bad signal".
"Should Japan continue to make provocative moves, China will be justified in taking more aggressive measures to safeguard its territorial integrity," said the editorial.
People's Daily Overseas Edition's front page commentary says Japan's "farce" must be checked, or the Senkaku dispute could get out of control.
The Global Times' Chinese editorial appeals for "sharp actions" from Beijing above and beyond diplomatic protests, regardless of whether ''Japan will also react sharply".
Meanwhile, newspapers including Hong Kong's Sing Tao Daily report that China's navy will begin a live fire drill in the area on Tuesday.
Foreign ministers from Asean countries and China are beginning a series of talks in the Cambodian capital Phnom Penh, with international reports saying that tension in the South China Sea would be key on the agenda.
However, Chinese academics told the Global Times that they do not think the South China Sea disputes would dominate the talks.
Amid ongoing tension, Shanghai Daily reports that the southern province of Hainan will launch a month-long wildlife survey on and around islands in the South China Sea.
China's inflation rate in June was 2.2% , which signifies a significant slowdown amid increasing worries of a renewed economic downturn.
Mr Wen made the comments during his tour in eastern Jiangsu province last week, where he said China is still facing "huge downward pressure".
People's Daily Overseas Edition reports on its front page that President Hu has urged the nation to work towards a "country of innovation" by 2020 in a speech he made in Beijing over the weekend.
"Chinese people have reason to be proud of the Made in China label, which has promoted its unprecedented economic growth," said a second China Daily editorial , "but this label needs to be changed to Created in China in the near future."
Hong Kong's Ming Pao Daily News says the species is believed to have been smuggled into China in recent years from the Amazon as ornamental fish.