The European Union's foreign policy supremo said Wednesday she would hold talks with Russia's foreign minister next month in Rome, as Brussels and Moscow seek to defuse tensions over Ukraine.

Catherine Ashton announced she would meet Sergei Lavrov in Rome on March 6. "Issues on international agenda to be discussed," she added in a statement posted on Twitter.

The United States Wednesday urged Russia to keep its word to respect the territorial integrity of Ukraine and warned against provocative actions after Moscow said it was boosting security measures in southern Crimea.

"We are making it clear that every country should respect the territorial integrity here, the sovereignty of Ukraine. Russia said it will do that, and we think it is important Russia keeps its word," Kerry said.

Ukraine's ousted president Viktor Yanukovych remains in the country, deputy general prosecutor Mykola Golomcha said Wednesday, without giving further details of the whereabouts of the leader who vanished over the weekend.

"We have information indicating Yanukovych is still in Ukraine," Golomcha told reporters in Kiev.

The foreign ministers of Hungary, Slovakia and Czech Republic will visit Kiev on Thursday where they hope to meet with the new government, Budapest said Wednesday.

Kiev's new leaders are due to unveil a unity cabinet on Wednesday afternoon following the dramatic ouster of pro-Russian president Viktor Yanukovych after months of protests sparked by his rejection of an association agreement with the EU.

The Council of Europe's anti-corruption group on Wednesday called on crisis-hit Ukraine to push for more transparency in the funding of political parties, warning its steps so far against fraud have been insufficient.

Ukraine to date has only implemented three of 16 recommendations made since 2011 by the Council's Group of States Against Corruption (GRECO), according to its published report.

A sovereign, independent and stable Ukraine is essential to security in Europe and beyond, NATO said Wednesday as tensions between pro- and anti-Russian factions stoked fears the country could break apart.

Such a Ukraine, "firmly committed to democracy and the rule of law, is key to Euro-Atlantic security," NATO said in a statement agreed by member state defense ministers.

Ukraine's ousted president Viktor Yanukovych drew up a large-scale "anti-terrorist" operation involving 22,000 security forces to "cleanse" protesters from Kiev, leaked documents show -- a plan opponents say would have caused even greater bloodshed.

Parts of the operation -- detailed in official memos handed to a lawmaker by security officials -- appear to have been set in motion when deadly clashes erupted last week between protesters and police. But for unknown reasons, others failed to materialize, allowing protesters to resist and eventually fight back.

Russian President Vladimir Putin on Wednesday ordered a snap check of the battle-readiness of the armed forces in the west and center of the country, including the area bordering Ukraine, as U.S. Secretary of State John Kerry warned that any Russian military moves in Ukraine would be a "grave mistake."

"The commander-in-chief has set the task of checking the capability of the armed forces to deal with crisis situations posing a threat to the military security of the country," said Defense Minister Sergei Shoigu, quoted by the Interfax news agency.

Cambodia has ended a ban on public protests imposed last month following a deadly crackdown on striking workers, an official said Wednesday, as the opposition vowed to mount fresh rallies.

Four civilians were killed when police opened fire on protesting textile factory workers demanding a minimum wage of $160 a month to make clothes for brands including Gap, Nike and H&M.

Ukraine's new pro-Western leaders on Wednesday disbanded the country's feared riot police as they sought to win confidence from the splintered and economically ravaged nation in their efforts to forge a unity government.

The interim authorities are grappling the with the dual threats of separatism and a looming debt default as they try to piece the ex-Soviet nation back together following the weekend ouster of pro-Russian president Viktor Yanukovych.