Russian President Vladimir Putin arrived in Beijing on his first visit to his country's vast neighbour since resuming the Russian presidency earlier this month. He later sat down for talks with Chinese President Hu Jintao that are expected to touch on the crisis in Syria as well as on Iran, bilateral trade and energy co-operation, and will join a regional summit later in the week.
Russia and China have repeatedly defied calls by the international community to confront Syria's regime over spiraling violence, saying they will not back steps that could lead to foreign intervention. Russia has long been a close ally of President Bashar Assad's regime, while Beijing opposes setting precedents that could potentially be applied to its troubled western regions of Tibet and Xinjiang.
China and Russia vetoed two U.N. Security Council resolutions which raised the threat of possible sanctions against Syria and have ruled out any Libya-style military action to protect civilians in Syria. The two also voted against a resolution Friday that condemned last month's massacre of more than 100 civilians in the cluster of villages known as Houla and called for an independent investigation.
The U.S. has pushed Russia to join international efforts for a political transition in Syria that would see Assad driven from power.
Putin, meanwhile, has sought to use Russia's burgeoning ties with Beijing as a counterweight to U.S. global predominance, and the sides have found common cause in rejecting Western calls for more open politics and respect for civil liberties.
Foreign Ministry spokesman Liu Weimin told reporters Tuesday that China and Russia both "oppose external intervention in the Syrian situation and oppose regime change by force."
Both countries also oppose further sanctions against Iran over its suspected drive to develop nuclear weapons.
On Wednesday and Thursday, the Putin and Hu will be among leaders attending the annual summit of the six-member Shanghai Cooperation Organization, a grouping of Russia, China and four Central Asian states seeking to boost regional integration and curb Western influence. The countries are also preparing for the U.S. departure from Afghanistan.
Liu said the summit leaders will issue a declaration on guidelines for cracking down on terrorism and building a region of "lasting peace and common prosperity." He did not give details.
Ties between the former Cold War rivals have grown steadily warmer over the course of Putin's decade-long dominance of Russian political life. Along with close co-ordination in international affairs, they've sought to boost economic ties, particularly in the energy sector, setting a target of raising bilateral trade to $100 billion by 2015 from $83.5 billion last year.
Despite that, disputes and mistrust linger. Moscow is unhappy with China's copying of Russian fighter jets and other military hardware and the sides have wrangled for years about the price of gas to be delivered by two Siberian pipelines. Russia prefers to link gas prices to oil prices, as it does in Europe, while China wants a lower price. If Russia's OAO Gazprom and China National Petroleum Corp. can reach a deal, deliveries are to start by 2015.
Putin's visit follows his attendance Monday at an EU summit in St. Petersburg at which he defended his country's human rights record, saying Russia has no political prisoners and dismissing criticism of a draconian bill that hikes fines for unsanctioned street rallies.
His visit to China is the first since his return to the presidency in May after stepping down in 2008 due to term limits.