WASHINGTON, April 22 (Reuters) - The United States said on Tuesday it had discouraged China from sending arms to Zimbabwe for now and had asked the southern African country's neighbors not to allow a ship carrying weapons to dock.

"Right now clearly is not the time that we would want to see anyone putting additional weapons or additional materiel into the system when the situation is so unsettled and when we have seen real and visible instances of abuses committed by the security forces," said State Department spokesman Tom Casey.

Zimbabwe has plunged into a political crisis after its March 29 election in which the main opposition Movement for Democratic Change says its leader Morgan Tsvangirai defeated 28-year incumbent President Robert Mugabe.

The country's authorities have yet to release the full results from the presidential election, leading to suspicions that they may be trying to steal the election.

Casey told reporters the United States urged Mozambique, South Africa, Angola and Namibia to bar the ship from docking.

The ship was barred from unloading in the South African port of Durban and Mozambique and Angola have since said it was not welcome. The Chinese government on Tuesday said the ship might return the cargo to China because it was impossible for land-locked Zimbabwe to receive the goods.

Casey said the United States was "pleased" by China's statement.

He added that U.S. Assistant Secretary of State Jendayi Frazier would leave Washington on Tuesday on a previously scheduled trip to South Africa, Zambia and Angola.

He said Zimbabwe's political crisis would come up in her meetings but suggested the arms shipment may not because most neighbors have refused the ship entry and China may recall it. (Reporting by Arshad Mohammed; Editing by Jackie Frank)