Cape Canaveral, Florida: Nasa intends to cancel plans to join Europe on a Mars sampling mission that is considered important to learning if life appeared beyond Earth as the US space agency balances out a virtually flat $17.7 billion (Dh64 billion) budget for 2013, officials said on Monday.

Nasa's proposal leaves Europe without a key partner for a proposed two-spacecraft mission to collect and return soil samples from Mars. The so-called Exobiology on Mars, or ExoMars, probes are targeted to launch in 2016 and 2018.

The United States wants to recast its Mars exploration programme to include both science and human exploration goals, Nasa Administrator Charlie Bolden said at a news conference to unveil the agency's proposed budget for the fiscal year beginning October 1. The agency's budget is $17.8 billion.

Solid plan

"Despite a constrained fiscal environment, this budget continues to aggressively implement the space exploration programme agreed to by the president and a bipartisan majority in Congress," Bolden said. "The time for debate about our future is over. We have a solid plan."