Pyongyang, Jun 16 (IANS): North Korean leader Kim Jong-un has sent birthday greetings to Chinese President Xi Jinping for the first time in five years.

Kim sent a letter and flowers to Xi on his 65th birthday on Friday, Efe news reported on Saturday.

Relations between the two neighbouring countries began to worsen after Kim in 2013 executed his uncle, Jang Song-thaek, the then number two of the regime and who had close ties with Beijing and pushed ahead with country's third nuclear test that same year.

China then joined the international initiative led by the US to impose sanctions on North Korea, which further worsened the North's ties with Beijing.

Relations between the two countries began to take a positive turn in 2018 in the current framework of detente with North Korea and, above all, after the two summits between Kim and Xi held in March and April.

Kim made a surprise visit to China between March 25 and 28 and met with Xi, marking his first visit abroad and first summit since he came to power in late 2011.

The two leaders met again in the Chinese city of Dalian in early May, amid preparations for the historic summit between Kim and US President Donald Trump on June 12 in Singapore.