The United States is calling on Zimbabwe's government to set a firm date for the country's presidential runoff election, and to take steps to assure the integrity of the process. Authorities in Zimbabwe said Wednesday the vote will be delayed until as late as July. VOA's David Gollust reports from the State Department.

State Department officials acknowledge that present security conditions would not allow for a fair and safe runoff election in Zimbabwe.

But they're lamenting the indefinite postponement announced Wednesday, saying the Harare government should establish a firm date along with measures to assure that the vote meets international standards.

Zimbabweans voted in the first round of the presidential contest March 29, but official results were not issued until May 2, more than a month later.

Opposition candidate Morgan Tsvangerai finished ahead of longtime President Robert Mugabe but without the outright majority needed to avoid a runoff.

Election law required a runoff within 21 days after the release of official figures. But it was announced Wednesday that the period is being extended to 90 days, meaning the vote might not occur until July.

At a news briefing, State Department Deputy Spokesman Tom Casey said a firm date should be set, along with steps to assure the integrity of the vote.

He said those should include barring the military from interfering in the electoral process, admitting international observers for both the runoff campaign and voting, and guaranteeing the opposition free expression.

"I think there's a whole list of things the Zimbabwean government can and should be able to do if it's serious about holding a runoff that's free and fair," he said.  "And the delay, without a date being set, just continues to, I think, underscore the fact that the government is not taking the steps it needs to."

Assistant Secretary of State for African Affairs Jendayi Frazer said Monday provisions for the runoff should include security guarantees for Mr. Tsvangirai.  He has been arrested several times since becoming opposition leader, and was severely beaten while in police custody last year.

In another development, Spokesman Casey said the United States has filed an official protest over what he termed harassment and inappropriate behavior by Zimbabwean police against U.S. Ambassador James McGee and other foreign diplomats.

In two incidents Tuesday, police stopped and subjected McGee and several colleagues to lengthy questioning after they had visited a hospital outside of Harare treating victims of recent post-election violence.

The State Department Wednesday renewed an advisory for U.S. citizens to defer non-essential travel to Zimbabwe because of ongoing political instability.

It said Zimbabwean security forces in advance of the runoff, are creating what was termed a "climate of intimidation and fear," and that there is an ongoing risk of arbitrary detention or arrest.