China has said the Group of Seven (G-7) nations must focus on the economic agenda and not meddle with the regional affairs.

Making comments after the G-7 leaders issued a statement criticising China's role in the South and East China Sea tensions, Beijing said the western bloc "should mind its own business rather than pointing fingers at others".

"...We believe that... they should all adopt impartial and fair positions, and not apply double standards or strike alliances, and especially not take actions to escalate or provoke regional tensions," Chinese Foreign Minister Wang Yi said, AFP reported.

At the summit in Japan, G7 leders raised concern over China's assertive action in the disputed waters amid territorial disputes with Japan and several Southeast Asian nations.

The summit statement did not mention Beijing, but the veiled comments were directed at China. The G7 members -- Britain, Canada, France, Germany, Italy, Japan and the United States -- called for countries to refrain from "unilateral actions which could increase tensions" and "to settle disputes by peaceful means".

Meanwhile, a commentary on official Xinhua news agency used harsh language for criticising G7 members, especially Japan.

The western bloc "should mind its own business rather than pointing fingers at others," the commentary said.

It also said Japan was trying "to take advantage of its G-7 summit host status and draw more 'allies and sympathisers' to isolate China."

The G7 also demanded that North Korea fully comply with United Nations Security Council resolutions and halt nuclear tests, missile launches and other "provocative actions".

The leaders of the world's top industrialised nations condemned Russia's "illegal annexation" of the Crimean peninsula from Ukraine and vowed to raise the 'costs 'on Moscow.

On global economy, the summit said growth remains moderate and below potential, while risks of weak growth persist.

"We have strengthened the resilience of our economies in order to avoid falling into another crisis and, to this end, commit to reinforce our efforts to address the current economic situation by taking all appropriate policy responses in a timely manner," the statement said.

It said a more forceful and balanced policy mix was needed to achieve a strong, sustainable and balanced growth pattern.