The Russian president's decision is announced today. The ousted Ukrainian president calls for Russian intervention because "the life and security and the rights of people, particularly in the southeast part in Crimea, are being threatened" and that there were "open acts of terror and violence".

New York City (AsiaNews/Agencies) - Russian President Vladimir Putin has ordered troops taking part in military exercises near the Ukrainian border to return to their bases, Russian state news agency RIA Novosti reported today, citing presidential spokesman Dmitry Peskov.

If true, this could reduce tensions heightened by statements made by Russia's UN envoy Vitaly Churkin. Showing a letter from the ousted president of Ukraine, Churkin said that Viktor Yanukovych had asked Russia for military intervention in Ukraine to restore law and order.

Although disputed by Ukrainian border officials, Putin's decision, if confirmed, comes after a day of rising tensions due to reports, later denied, that Russian forces had issued a surrender order to Ukrainian forces in Crimea, which has led to fears that fighting might break out.

The ultimatum to Ukrainian forces in Crimea to surrender, Interfax said, was issued by Alexander Vitko, the fleet's commander, quoting a Ukrainian Defence Ministry as the source.

Later, Interfax quoted a Russian official at the fleet's headquarters as saying that they had not issued the ultimatum.

In view of this, Russia's UN Ambassador Vitaly Churkin aggravated the situation by reading a statement attributed to Ukraine's fugitive president, whereby "as the legitimately elected representative" Yanukovych believes "Ukraine is on the brink of civil war."

The Russian diplomat quoted Yanukovych as saying "the life and security and the rights of people, particularly in the southeast part in Crimea, are being threatened" and that there were "open acts of terror and violence".

Similarly, speaking at the UN Human Rights Council in Geneva, Russian Foreign Minister Sergei Lavrov had justified the use of troops in Crimea as a necessary for the protection of his country's citizens living there.

Meanwhile, the Pentagon said it was putting on hold all military-to-military engagements between the US and Russia. These include exercises, bilateral meetings, port visits and planning conferences. However, "there has been no change to our military posture in Europe or the Mediterranean".

• russia
• ukraine
• crisis
• crimea
• invasion
• tensions