China on Friday offered its clearest signal yet it was ready to work with North Korea toward warmer ties this year, vowing efforts to boost friendship and cooperation with Pyongyang.

China’s foreign ministry spokesman Hong Lei made the comments in a statement, which also reconfirmed that Beijing sent a message of congratulations to North Korea on the birthday of its young leader Kim Jong-un.

“In the new year, the Chinese side will push forward its traditional friendship and cooperation with the DPRK (North Korea) in keeping with the principles of carrying on the tradition, looking to the future, developing good-neighborly and friendly relations, and enhancing cooperation,” Hong said in the statement.

During a regular press briefing Thursday, Hong told reporters that China had sent the congratulatory message to North Korea but did not comment on bilateral relations.

His comments are widely seen as stressing the principle of North Korea-China relations, which was approved by North Korea’s late leader Kim Jong-il and then Chinese President Jiang Zemin in 2001. Over the past year, Chinese officials have not made comments to that effect.

Political ties between China and its only treaty ally, North Korea, remain strained, particularly after the North’s third nuclear test in February 2013.

In what many analysts believe was a message to North Korea, Chinese President Xi Jinping paid a state visit to South Korea last year, breaking a long-standing tradition by Chinese heads of state of visiting Pyongyang before Seoul.

The congratulatory message by China on Kim’s birthday also came as North Korea is trying to deepen its ties with Russia.

With international pressure mounting on North Korea for its nuclear program and dismal human rights record, the North’s young leader sent his special envoy to Moscow late last year and the envoy met with Russian President Vladimir Putin.

Russia has also said that it invited Kim to Moscow in May this year to attend a ceremony marking the 70th anniversary of the victory over Nazi Germany.

Kim, who inherited power after the death of his father in late 2011, has yet to visit China. (Yonhap)