Gambian President Yahya Jammeh is refusing to step down despite efforts to persuade him to leave office ahead of a deadline set by Senegal.
Adama Barrow is due to be inaugurated as the new president on Thursday, and West African military forces are poised to move in.
Mauritanian President Mohamed Ould Abdel Aziz met Mr Jammeh for last-minute talks before flying on to meet Senegal’s President Macky Sall.
Mr Barrow won elections last month.Senegalese troops remain stationed at the Gambian border, as the deadline for Mr Jammeh to stand down passed at midnight.
The threat of military action is supported by Nigeria and other states in the region.
However Gambian army chief Ousman Badjie said his troops would not fight Senegalese forces should they enter into the country, AFP news agency reports.
“We are not going to involve ourselves militarily, this is a political dispute,” he said. “I am not going to involve my soldiers in a stupid fight. I love my men.”