אָ֧ז נִדְבְּר֛וּ יִרְאֵ֥י יְהוָ֖ה אִ֣ישׁ אֶת־רֵעֵ֑הוּ וַיַּקְשֵׁ֤ב יְהוָה֙ וַיִּשְׁמָ֔ע וַ֠יִּכָּתֵב סֵ֣פֶר זִכָּר֤וֹן לְפָנָיו֙ לְיִרְאֵ֣י יְהוָ֔ה וּלְחֹשְׁבֵ֖י שְׁמֽוֹ׃
그 때에 여호와를 경외하는 자들이 피차에 말하매 여호와께서 그것을 분명히 들으시고 여호와를 경외하는 자와 그 이름을 존중히 생각하는 자를 위하여 여호와 앞에 있는 기념책에 기록하셨느니라
Sefer HaTashbetz
From all this (the answer to your question) becomes clear. Someone who repents and regrets his sins and wants to immigrate to the Land of Israel: repentance atones; immigration to the Land of Israel adds merit and saves him from sin all (the rest) of his days. And your question, if circumstances beyond his controlled stopped him, and he did not complete his mitzvah, is it still considered a merit for him, as if he did complete it - our sages have already said in the first chapter of Kiddushin (40a), “The Creator joins a good thought to an action, as it is stated: “Then they that feared the Lord spoke one with the other, and the Lord listened, and heard, and a book of remembrance was written before Him, for them that fear the Lord, and that think upon His name” (Malachi 3:16). What is the meaning of the phrase “and that think upon His name”? Rav Asi said: Even if a person intended to perform a mitzva but due to circumstances beyond his control he did not perform it, the verse ascribes him credit as if he performed the mitzva. And may the Omnipresent One help him with his goal, like the king of the Kuzars said to the rabbi when he left him to immigrate to the Land of Israel. (Kuzari 5:28)