US President Donald Trump may soon have a lake named after him following proposals to christen a contested Balkan reservoir in his honour. He already has golf clubs and hotels named after him.

The lake in question is a 24-kilometre stretch of water straddling the border of former war foes Serbia and Kosovo, who both claim ownership and have different names for it.

Three quarters of the reservoir lies in Kosovo, while the rest is in Serbia. But the dispute is not just a quarrel about the name.

A huge banner appeared Thursday on Kosovo’s side of the reservoir reading “Lake Trump”, while another hung over a bridge thanked Trump for “bringing peace” following recent US-brokered agreements between Kosovo and Serbia.

The tussle over ownership of the lake — called Ujman in Kosovo and Gazivode in Serbia — is one of many disputes still haunting the neighbours 20 years after they broke apart in war.

After the banners emerged, Kosovo’s Prime Minister Avdullah Hoti wrote on Twitter that he “welcomed” the proposal to rename the body of water “Lake Trump” in honour of the “historic economic normalization agreement” signed at the White House in early September.

The agreements, which analysts said were light on substance despite Trump’s insistence on their “historic” nature, included a commitment to a feasibility study for “sharing” the lake.

According to Trump advisor Richard Grenell, who led talks on the agreements, the idea of Lake Trump was originally a joke.

“There was this incredible fight about the name so I kind of jokingly said… well, I’m going to keep referring to it as Lake Trump”, Grenell said in an interview with a US talk show.

“And both leaders jumped at it and said -– I’m OK with Lake Trump, let’s call it Lake Trump”, he added.

The said lake is the crucial source of drinking water for more than a third of Kosovo’s 1.8 million population, and a cooling source for the coal plants that produce almost all of Kosovo’s electricity.

Serbia, which still does not recognise its former province’s independence, considers the lake its property.

Locals in the surrounding area, a northern part of Kosovo home mainly to ethnic Serbs, were unclear of who was behind the naming initiative.