Around 20 countries including China have refused Norway's invitation to Friday's ceremony awarding the Nobel Peace Prize to jailed Chinese dissident Liu Xiabao.
Most have close ties to China, do not want to anger Beijing or have a tendency to take a hard line against their own dissidents.
Those who have said they are staying away are Afghanistan, Algeria, China, Colombia, Cuba, Egypt, Iraq, Iran, Kazakhstan, Morocco, Pakistan, Russia, Saudi Arabia, Sri Lanka, Sudan, Tunisia, Venezuela and Vietnam.
Ukraine and the Philippines had at first declined their invitations, but Nobel Institute director Geir Lundestad on Thursday said they had changed their minds.
Serbia, which had initially refused the invitation, Thursday said it would be sending a representative after all.
At the same time, said Lundestad, "we believe that Argentina will not be coming, or at least will not be represented by the ambassador."
Russia, which signed trade agreements with China last month worth USD 8.5 billion, has officially pleaded prior engagements for its absence.
Other countries like Pakistan and Sri Lanka have economic and defence ties with China, while Iraq, Iran and Saudi Arabia supply it with oil.
Iran also relies on Chinese support in the UN Security Council to fight sanctions against its nuclear programme, and will not have forgotten the Peace Prize awarded to one of its own dissidents, Shirin Ebadi, in 2003.
Most of the 65 countries with embassies in Oslo will be represented, including Western powers from the European Union and the United States, as well as Japan, which has a territorial dispute with China.
Emerging economic powers which are potential rivals rather than partners of China will also be there, including Brazil, lndia, Indonesia, South Africa and South Korea.