Abraham won two England caps in a pair of friendlies in November 2017 but remains eligible for a change of allegiance to Nigeria.
"It is always a privilege to be wanted by both nations," Abraham told reporters.
"I love both nations and for me I am clearly doing something right for Chelsea.
"My time will come. I haven't made a decision yet. I am focusing on the club."
The admission comes despite a claim from Nigeria boss Gernot Rohr that Abraham had been "assured" of a Three Lions call-up.
"They [Abraham and Chelsea team-mate Fikayo Tomori] are both interesting players, but we have made our immediate plans without Tammy Abraham and Fikayo Tomori," Rohr added in an interview with the BBC.
Abraham represented England at the recent European Under-21 Championships.
He has been a regular starter under Frank Lampard since returning to Stamford Bridge from a loan spell at Aston Villa.
The 21-year-old has netted seven goals in seven Premier League fixtures at the start of the season, impressing in a lone centre-forward role.
Abraham will be expected to retain a place in Chelsea's line up for their latest domestic clash away at Southampton this Sunday.