No.

Only the US government and the congress can substantially impact the US' policy of the World Trade Organization. The USTR is the executive branch that acts on behalf of the US government at WTO. Reversing the decline of the WTO's appellate body is virtually impossible unless the US government drops its policies that aim to hobble its arbitration function.

The EU has entered into treaties on bilateral arbitration with countries like Canada and Norway and hopes such voluntary deals can push the 164 WTO members to reach multilateral agreements on arbitration. However, the US, which has simply decided to hamstring the appellate body to exclude frequent charges at the WTO by 'small countries,' can obviously not possibly close ranks.