China, which consistently says it opposes interference in other countries' internal affairs, is looking to "maintain principles" on Ukraine, it said Monday after Russia insisted the two were in broad agreement.

Moscow has appeared keen to stress that it has a major international ally on its military intervention in Ukraine, and Beijing frequently backs its positions against Western powers on thorny issues, such as the protracted conflict in Syria.

But analysts say China is torn between wanting to support Russia and keeping to its longtime opposition to foreign intervention, especially given its own separatist issues in the far-western region of Xinjiang.

When asked about Ukraine at a regular press briefing on Monday, Chinese foreign ministry spokesman Qin Gang answered indirectly.

"China has always upheld the principles of diplomacy and the fundamental norms of international relations," he said.

"At the same time we also take into consideration the history and the current complexities of the Ukrainian issue. It could be said that China's position is to both maintain principles while also seeking to be realistic."

Qin also referred to his statement posted on the ministry's website a day earlier, which said on the one hand that "China has long maintained a principle of noninterference in internal affairs (of other countries), and respects Ukraine's independence, sovereignty and territorial integrity".

But it also noted that "there are reasons that the Ukrainian situation is what it is today".

- 'A statement nobody can understand' -

Niu Jun, a professor of international affairs at Peking University, said China wanted to maintain its relationship with Russia yet had strong concerns about foreign intervention.

"It's all very inconvenient," he said. "That's why they came out with a statement nobody can understand.

"What this statement is really saying is, 'what Russia did was not right and China does not want to support this military invasion'. But China also wants to support Russia, so it came up with excuses" such as Russia's history with Crimea and Ukraine's internal situation, he said.

"Yet at the same time they realise this excuse doesn't hold water, so they also threw in a mention of sovereignty and territorial integrity."

Earlier, Moscow's foreign ministry said in a statement that minister Sergei Lavrov and his Chinese counterpart Wang Yi in a phone call noted "broadly coinciding points of view of Russia and China over the situation that has developed in the country and around it".

Yet China's account of the conversation was less direct, saying that the two men "thoroughly exchanged views on the matter" and agreed that "appropriately resolving" the situation was important to regional peace and stability.

Russia has found itself internationally isolated over its covert military intervention in Ukraine and on Monday its stocks and currency collapsed amid fears of a prolonged campaign.

The other members of the G8 on Sunday released a statement condemning Russia for violating international law and suspending their participation in a G8 summit set to be held in Sochi in June.

China is not a member of the G8.

China and Russia cooperated on vetoing three UN Security Council resolutions to put pressure on Syrian President Bashar al-Assad, although they voted through a resolution this month on allowing in humanitarian aid convoys.