Human Rights Watch urged Jordan on Sunday to deny entry to Sudanese President Omar al-Bashir or arrest him over alleged war crimes in Darfur if he visits this week.
Bashir has reportedly been invited to a summit of the Arab League to take place in Jordan on Wednesday.
"Jordan should deny entry to Sudanese President Omar al-Bashir or arrest him if he enters the country," New York-based HRW said in a statement.
The Sudanese president is wanted by the International Criminal Court for alleged war crimes, crimes against humanity and genocide related to the conflict in Darfur.
The Hague-based court issued arrest warrants for Bashir in 2009 and 2010, but he has so far evaded arrest and steadfastly denies the charges.
"Jordan would be defying its international obligations as an ICC member if it allows Bashir to visit without arresting him," said Elise Keppler, associate international justice director at HRW.
The conflict in Darfur, a region the size of France, erupted in 2003 when ethnic minority rebels took up arms against Bashir's Arab-dominated government in Khartoum, accusing it of marginalising the region economically and politically.
At least 300,000 people have been killed in Darfur and another 2.5 million displaced since the conflict erupted, the United Nations says.
In 2015, South Africa refused to arrest Bashir when he attended an African Union summit there, claiming he had immunity as the head of an AU member state.
The ICC is to hold a public hearing on April 7 to probe whether South Africa -- a signatory to the Rome Statute of the world war crimes court -- failed in its duty in refusing to do so.