内容摘要：However, the nutrients can lead to excessive growth of algae in waterways, starving the river of oxygen and killing fish.

However, the nutrients can lead to excessive growth of algae in waterways, starving the river of oxygen and killing fish.

The prime minister's announcement comes after the former head of the Army, Lord Dannatt, told the BBC theSpeaking to BBC Breakfast, he said sending troops to Ukraine would come at a "considerable cost" and require an increase in funding for the military.

"Frankly, we haven't got the numbers and we haven't got the equipment to put a large force onto the ground for an extended period of time at the present moment," he said.Former MI6 chief Sir John Sawers also warned that any peacekeeping force sent to Ukraine after the war must have "a very clear mandate" to ensure a ceasefire agreement holds.Sir Keir, who is due to visit President Donald Trump in Washington later this month, said a "US security guarantee is essential for a lasting peace, because only the US can deter Putin from attacking again".

He is also meeting other European leaders on Monday over concerns the US is moving forward with Russia on peace talks that will lock out the continent.Meanwhile, US Secretary of State Marco Rubio is to meet Russian officials in Saudi Arabia in the coming days, US officials say.

On Saturday, the US special envoy to Ukraine, Keith Kellogg, said European leaders would be consulted only and not take part in any talks between the US and Russia.

A senior Ukrainian government source told the BBC on Sunday thatin January, condemned Trump's calls for the US to take back the Panama Canal, to acquire Greenland and to make Canada the 51st state.

"What the hell's going on here? What president ever talks like that? That's not who we are," Biden told the BBC's Nick Robinson."We're about freedom, democracy, opportunity, not about confiscation."

Greenland, the world's largest island, has been controlled by Denmark for about 300 years. The island governs its own domestic affairs, but foreign and defence policy decisions are made in Copenhagen.The US has long had a security interest in the island. It has had a military base there since World War Two, and Trump may also have an interest in the rare earth minerals that could be mined.