Washington is willing to co-operate with the new China-led infrastructure investment bank, according to an envoy of United States President Barack Obama on Monday.
Some observers said the comment rules out the possibility of the US joining the Asian Infrastructure Investment Bank.
US Treasury Secretary Jacob Lew, who is making a visit to China as special envoy of Obama, said Washington is looking forward to cooperating with the new bank, Xinhua News Agency reported.
The US welcomes and supports proposals that are helpful to infrastructure con-struction, the report said.
Lew said co-operation can be carried out through the China-US Strategic and Economic Dialogue, the World Bank, the AIIB and any other mechanisms accepted by the two countries.
He made the comments while meeting with Premier Li Keqiang on Monday, Xinhua said, quoting Vice-Minister of Finance Zhu Guangyao.
Lew said in his hourlong talks with Li that the US welcomes China playing a bigger role in infrastructure construction in Asia and is willing to deepen co-operation on bilateral and multilateral platforms in this regard.
Li urged the US to approve International Monetary Fund quota and governance reforms as soon as possible, which the US Congress has prevented from taking effect for more than two years. The US is the only member country with the power to veto decisions by the IMF, which is based in Washington DC.
In an earlier meeting on Monday with Vice-Premier Wang Yang, Lew said that promoting innovation and opening markets are of mutual interest to both countries.
The meetings came ahead of Tuesday's deadline for countries to apply to become founding members of the AIIB. Egypt applied on Monday, taking the total number of nations to 44 across four continents.
Ding Yifan, an economist at the State Council's Development Research Center, said Lew's statement indicates that the US is unlikely to join the new bank.
But Ding said Washington has softened its stance by opening the door to co-operation with the bank.
The US has criticised Britain after the UK's surprise decision to join the AIIB.