The invitation came during a meeting between Li and Singapore Deputy Prime Minister Tharman Shanmugaratnam Tuesday on the sidelines of an economic forum in the Chinese city of Dalian, the release from the Singapore Prime Minister's office said.
A date has not been set.
Ties between the two had been strained, with Singapore's leader conspicuously absent from China's flagship summit on its Belt and Road Initiative in May and the impounding in Hong Kong of nine armored vehicles belonging to Singapore last year.
"Singapore has been drifting more towards the opposite side (the United States)," said Zhang Baohui, a professor of politics at Hong Kong's Lingnan University.
Analysts interpreted the seizure as China sending a message to Singapore,
which had strengthened military ties with the US and taken a tough stance on the South China Sea dispute, urging China to abide by an international tribunal that ruled its claims to the waters were unlawful.
The troop carriers were seized in Hong Kong after being used in training exercises in Taiwan, which China views as a renegade province.
"China wanted to show its displeasure with Singapore and let it know about it," Zhang said. "At the same time, China very much wants to keep Singapore as neutral as possible."
Pivoting to Beijing
Singapore's efforts to mend fences comes after other southeast Asian countries have appeared to strengthen ties with China, with the Philippines, a traditional US ally,
all pivoting to Beijing.
During the meeting on Tuesday, Chinese premier lauded recent cooperation between the two countries and the city-state's role in mediating the relationship between China and the Association of Southeast Asian Nations (ASEAN) during their meeting, according to China's state-run Xinhua news.
Though Singapore does not claim any territory in the disputed waters, it has often played a mediation role between China and other claimants, including Vietnam, Taiwan, Brunei, Malaysia and Indonesia.
In the past, it's also played a mediator role in confrontations between China and Taiwan.
"Singapore's position is very much shaped by geopolitics and its own identity," Zhang told CNN. "Compared to other ASEAN countries, Singapore is more apprehensive about China's rise."
Zhang does not believe that visit will change Singapore's stance. He believes Singapore will continue to improve its relationships around the globe with the West and China. But he does think it will lead to more co-operation on China's grand "One Belt One Road" economic project, as it likely doesn't want to miss out on the potential economic gains of a partnership.