Washington DC – Ahead of the inauguration of US president-elect Joe Biden on Wednesday, countries around the world expressed cautious hope for a reset in relations while prioritizing their own interests.

China was hoping for "a collaboration beneficial to both sides," a spokesperson for the Foreign Ministry in Beijing said.

But China would preserve its own interests and national security and not be defamed by the United States, the spokesperson added.

The comments come after the designated incoming secretary of state, Anthony Blinken, named relations with China as a central challenge for the US on Tuesday.

Meanwhile, arch-rival Iran said it was generally ready to clear its differences with the US. But the ball was in Washington's court, President Hassan Rouhani said on Wednesday.

"Everything they do, we will do exactly the same ... no more, no less," Rouhani said on state television.

With reference to the 2015 nuclear deal, Rouhani said that if Biden was serious in fulfilling its international obligations towards Iran, Tehran would do the same.

Outgoing President Donald Trump had left the deal and imposed unilateral sanctions on Iran, after which Tehran stopped fulfilling the technical requirements of the deal.

Rouhani said Iran would return to its obligations if the rest of the deal – namely scrapping the sanctions – was implemented as well. He declined a full or partial renegotiation of the agreement.