The United States said on Thursday it is suspending all training programmes with Burundi's police and army.

Intensifying its pressure on President Pierre Nkurunziza, the US also said it will rescind Burundi's eligibility for the Agoa trade preference programme and stopped short of threatening to halt its support for Burundian forces deployed outside the country.

The US State Department said Mr Nkurunziza had disregarded the terms of an agreement that ended a civil war in Burundi by running for a third term, adding that his insistence on remaining in power has resulted in dozens of deaths, the exodus of some 144,000 refugees and and "a freefall in the Burundian economy causing suffering to millions of Burundians."

The US said it was joining the United Nations, African Union and European Union in urging Mr Nkurunziza "to place the welfare of Burundi’s citizens above his own political ambitions."

"Mr Nkurunziza should postpone the presidential election scheduled for July 15 and open a dialogue with opposition parties and civil society groups," the US urged in a statement.

Until now, Washington has stopped short of threatening to reduce its support for Burundian troops taking part in missions outside the country. Burundi contributes more than 5000 soldiers to Amisom, the AU's 22,000-member military mission stationed in Somalia. Burundi also supplies nearly 1300 troops to UN peacekeeping operations.

While the US did not specifically mention Burundi's participation in Amisom in its statement on Thursday, the possibility of reduced US aid to Burundian forces in Somalia and other countries was mooted in the warning, saying that the election-related crisis could "hamper our ability to support the important contribution of the Burundian military to international peacekeeping."

The threat of suspension from Agoa was likewise posed for the first time.

"During our upcoming review of Burundi’s eligibility for the trade preferences available to it under the African Growth and Opportunity Act, we will be taking into consideration ongoing violence and instability and the government of Burundi’s lack of respect for the rule of law in determining their eligibility for these trade preferences," the statement read.